Method for image data print control, electronic camera and camera system

ABSTRACT

A method for image data print control includes: obtaining subject image data which is obtained by capturing an image of a subject formed through a photographic optical system and output by an image-capturing element having a plurality of pixels; obtaining a distance to the subject; obtaining a number of pixels provided at the image-capturing element; obtaining a pixel pitch at the image-capturing element; obtaining a focal length of the photographic optical system; and calculating a printing resolution so as to print the image of the subject in a size equal to a size of the subject by using the subject image data, based upon the distance to the subject, the number of pixels at the image-capturing element, the pixel pitch at the image-capturing element and the focal length of the photographic optical system.

[0001] This application is a continuation in part of U.S. patentapplication Ser. No. 10/115,912 filed Apr. 5, 2002

INCORPORATION BY REFERENCE

[0002] The disclosures of the following priority applications are hereinincorporated by reference:

[0003] Japanese Patent Application No. 2001-107244 filed Apr. 5, 2001

[0004] Japanese Patent Application No. 2001-107245 filed Apr. 5, 2001

[0005] Japanese Patent Application No. 2001-247839 filed Aug. 17, 2001

[0006] U.S. patent application Ser. No. 10/115,912 filed Apr. 5, 2002

BACKGROUND OF THE INVENTION

[0007] 1. Field of the Invention

[0008] The present invention relates to a method for image data printcontrol, an electronic camera and a camera system.

[0009] 2. Description of the Related Art

[0010] After a photographing operation is performed in an electroniccamera, the data constituting the photographed image are normally takeninto a personal computer via a recording medium such as a memory card, acommunication cable or the like in the related art. The image thus takeninto the personal computer can be printed out by utilizing a printer.The image can be printed in this situation by specifying the printingsize and the printing resolution in, for instance, a printingapplication software program.

[0011] However, while the image can be printed in a desired printingsize at a desired printing resolution, there is no appropriate methodthat may be adopted to print the photographed subject in original size(magnification factor 1) or to print the photographed subject at aspecified magnification factor.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to provide a method forimage data print control that enables printing of a subject image at amagnification factor of 1 and also at a specified magnification factor,and an electronic camera and a camera system that are capable ofperforming a photographing operation by taking into considerationpossible eventualities of printing at a magnification factor of 1 or ata specified magnification factor to facilitate a printing operation at amagnification factor of 1 or at a specified magnification factor.

[0013] A method for image data print control according to the presentinvention, comprises: obtaining subject image data which is obtained bycapturing an image of a subject formed through a photographic opticalsystem and output by an image-capturing element having a plurality ofpixels; obtaining a distance to the subject; obtaining a number ofpixels provided at the image-capturing element; obtaining a pixel pitchat the image-capturing element; obtaining a focal length of thephotographic optical system; and calculating a printing resolution so asto print the image of the subject in a size equal to a size of thesubject by using the subject image data, based upon the distance to thesubject, the number of pixels at the image-capturing element, the pixelpitch at the image-capturing element and the focal length of thephotographic optical system.

[0014] In this method for image data print control, it is preferredthat: obtaining a printing magnification factor is further provided; andafter the printing magnification factor is obtained, a printingresolution is calculated so as to print the image of the subject in asize achieved by enlarging the size of the subject by the printingmagnification factor that has been obtained by using the subject imagedata, based upon the distance to the subject, the number of pixels atthe image-capturing element, the pixel pitch at the image-capturingelement and the focal length of the photographic optical system.

[0015] An electronic camera according to the present inventioncomprises: a photographic optical system; an image-capturing elementhaving a plurality of pixels that captures an image of a subject formedthrough the photographic optical system and outputs image dataconstituting the image thus obtained; a range finding device thatdetects a distance to the subject; a calculating device that obtains anumber of pixels at the image-capturing element, a pixel pitch at theimage-capturing element and a focal length of the photographic opticalsystem, and calculates a printing resolution so as to print the image ofthe subject in a size equal to a size of the subject by using thesubject image data, based upon the distance to the subject that has beendetected, the number of pixels at the image-capturing element, the pixelpitch at the image-capturing element and the focal length of thephotographic optical system; and a recording control device that recordsthe printing resolution that has been calculated into a recording mediumtogether with the image data.

[0016] Another electronic camera according to the present inventioncomprises: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a printingresolution calculating unit that calculates a printing resolution so asto print the subject image based upon image information output by theimage-capturing unit in a size substantially equal to the photographicrange, based upon the photographic range and the number of pixelsprovided at the image-capturing unit; and a storage control unit thatstores the printing resolution into a storage area together with theimage information.

[0017] Another electronic camera according to the present inventioncomprises: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a magnificationfactor setting unit that sets a printing magnification factor; aprinting resolution calculating unit that calculates a printingresolution so as to print the subject image based upon image informationoutput by the image-capturing unit in a size substantially equal to asize achieved by multiplying a size of the photographic range by theprinting magnification factor, based upon the photographic range, anumber of pixels provided at the image-capturing unit and the printingmagnification factor; and a storage control unit that stores theprinting resolution into a storage area together with the imageinformation.

[0018] In the above electronic cameras, it is preferred that: a displaymonitor that selectively displays a subject image captured by theimage-capturing unit and a subject image based upon the imageinformation stored in the storage area, is further provided; and adisplay magnification factor representing a ratio of a size of a displayrange of the display monitor and a value obtained by dividing the numberof pixels by the printing resolution is displayed at the display monitortogether with the subject image.

[0019] In the above electronic cameras, it is preferred that: thephotographic optical system is constituted of a zoom optical system; anexecution mode in which the printing resolution is calculated and theprinting resolution is stored into the storage area and a non-executionmode in which no printing resolution is calculated and stored areprovided; a mode setting unit that selectively sets either the executionmode or the non-execution mode is provided; a zoom changing unit thatchanges a focal length of the zoom optical system is provided; and azoom control unit that controls the zoom changing unit so that a zoomposition of the zoom optical system achieves a predetermined focallength when the mode setting unit sets the execution mode, is provided.In this case, it is preferred that the zoom control unit controls thezoom changing unit so that the zoom optical system enters a macrophotographing state when the mode setting unit sets the execution mode.Furthermore, it is preferred that a clearing unit that clears the macrophotographing state and a mode control unit that switches from theexecution mode to the non-execution mode when the clearing unit clearsthe macro photographing state in the execution mode, are provided.

[0020] In the above electronic cameras, it is preferred that a warningunit that engages in a warning operation when the subject distance isnot within a predetermined range, is provided.

[0021] A camera system according to the present invention comprises: anelectronic camera; and a printing device. The electronic cameracomprises: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a printingresolution calculating unit that calculates a printing resolution so asto print the subject image based upon image information output by theimage-capturing unit in a size substantially equal to the photographicrange, based upon the photographic range and a number of pixels providedat the image-capturing unit; and a storage control unit that stores theprinting resolution into a storage area together with the imageinformation, and the printing device prints the subject image based uponthe printing resolution and the image information stored in the storagearea.

[0022] Another camera system according to the present inventioncomprises: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a printingresolution calculating unit that calculates a printing resolution so asto print the subject image based upon image information output by theimage-capturing unit in a size substantially equal to the photographicrange, based upon the photographic range and a number of pixels providedat the image-capturing unit; and a printing device that prints thesubject image based upon the printing resolution and the imageinformation.

[0023] In the above camera systems, it is preferred that: an imageprocessing unit that processes the image information if the printingresolution is not within a printing resolution range set in advance, soas to achieve a predetermined printing resolution within the printingresolution range, is provided; and the printing device prints thesubject image based upon the image information having been processed atthe image processing unit and the predetermined printing resolution.

[0024] Another electronic camera according to the present inventioncomprises: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a printingresolution calculating unit that calculates a printing resolution so asto print the subject image based upon image information output by theimage-capturing unit in a size substantially equal to the photographicrange, based upon the photographic range and a number of pixels providedat the image-capturing unit; a storage control unit that stores theprinting resolution into the storage area together with the imageinformation; a display monitor that displays the subject image capturedby the image-capturing unit; a printing size storage unit having storedtherein at least one of various printing sizes; and a monitor controlunit that controls the display monitor so as to display at least one ofmarks indicating the printing sizes together with the subject image.

[0025] In this electronic camera, it is preferred that: a reproductionmode in which the subject image based upon the image information storedin the storage area is displayed at the display monitor, is provided;and when the reproduction mode is selected, the monitor control unitcontrols the display monitor so as to display the mark together with thesubject image.

[0026] Also, it is preferred that an input unit that inputs the printingsizes to the printing size storage unit is provided.

[0027] Also, it is preferred that the mark displayed at the displaymonitor is a rectangular frame indicating the printing size. In thiscase, it is preferred that: a correction unit that captures an image ofa reference rectangular frame having a size equal to the printing sizeand corrects the printing resolution based upon a printing resolution atwhich the rectangular frame corresponding to the printing size matchesthe image of the reference rectangular frame on the display monitor anda value obtained by dividing the number of pixels by the size of thereference rectangular frame, is provided; and the storage control unitstores the printing resolution having been corrected by the correctionunit into the storage area together with the image information.

[0028] Also, it is preferred that the monitor control unit controls thedisplay monitor so as to display a center mark indicating a centralposition of the display monitor.

[0029] Also, it is preferred that: a selection unit that selects one ofthe printing sizes stored in the printing size storage unit, and adecision-making unit that makes a decision as to whether or not thephotographic range calculated by the photographic range calculating unitis equal to or smaller than the printing size selected by the selectionunit, are provided; and the monitor control unit controls the displaymonitor so as to display a decision making mark indicating decisionresults obtained at the decision-making unit.

[0030] Another electronic camera according to the present inventioncomprises: a zoom changing unit that changes a focal length of a zoomlens; an image-capturing unit that executes photoelectric conversion fora subject image projected by the zoom lens onto an image-capturing area;a range finding unit that detects a distance to a subject; aphotographic range setting unit that sets a size of a photographic rangeat a subject position; and a zoom control unit that controls the zoomchanging unit based upon the photographic range that has been set andthe subject distance so that the subject within the photographic rangeis projected almost over the entirety of the image-capturing area.

[0031] Another electronic camera according to the present inventioncomprises: a zoom changing unit that changes a focal length of a zoomlens; an image-capturing unit that executes photoelectric conversion foran image of a subject projected by the zoom lens onto an image-capturingarea; a range finding unit that detects a distance to a subject; a modesetting unit operated to set a specified range photographing mode inwhich a size of the photographic range at a subject position is fixed ata predetermined size; and a zoom control unit that controls the zoomchanging unit based upon the photographic range and the subject distancewhen the specified range photographing mode is set so that the subjectwithin the photographic range is projected almost over the entirety ofthe image-capturing area.

[0032] In this electronic camera, it is preferred that: a magnificationfactor setting unit that sets a printing magnification factor is furtherprovided; and the mode setting unit fixes the size of the photographicrange at the subject position to a size calculated by dividing thepredetermined size by the printing magnification factor.

[0033] Also, it is preferred that a size setting unit operated to setthe predetermined size is further provided.

[0034] Also, it is preferred that there is provided a display monitor atwhich a subject image based upon image information provided by theimage-capturing unit and a range indicator mark indicating a rangesubstantially corresponding to the photographic range superimposed onthe subject image are brought up on display when the focal length of thezoom lens is at a maximum and a size of a range of the subject projectedalmost over the entirety of the image-capturing area is larger than thesize of the photographic range. In this case, it is preferred that astorage control unit that stores image information over the rangeindicated by the range indicator mark into a storage area is furtherprovided. Furthermore, it is preferred that the storage control unitstores the predetermined size into the storage area in correspondence tothe image information.

[0035] Also, it is preferred that there are further provided: anelectronic zoom unit that electronically enlarges a part of a subjectimage achieved based upon image information provided by theimage-capturing unit; and an electronic zoom control unit that controlsthe electronic zoom unit when the focal length of the zoom lens is at amaximum and a size of a range of the subject projected almost over theentirety of the image-capturing area is larger than the size of thephotographic range, so as to enlarge an image corresponding to thesubject within the photographic range in the subject image achievedbased upon the image information from the image-capturing unit to a sizematching a size of the subject image.

[0036] Also, it is preferred that there is further provided a warningunit that issues a warning if the focal length of the zoom lens is at aminimum and a size of a range of the subject projected almost over theentirety of the image-capturing area is smaller than the size of thephotographic range.

[0037] Also, it is preferred that there is further provided asub-sampling unit that electronically sub-samples the subject image whenthe focal length of the zoom lens is at a minimum and a size of a rangeof the subject projected almost over the entirety of the image-capturingarea is smaller than the size of the photographic range.

[0038] Also, it is preferred that there is further provided a displayunit at which a mark indicating the predetermined size is displayed.

[0039] Another electronic camera according to the present inventioncomprises: a zoom changing unit that changes a focal length of a zoomlens; an image-capturing unit that executes photoelectric conversion foran image of a subject projected by the zoom lens onto an image-capturingarea; a range finding unit that detects a distance to a subject; a modesetting unit operated to set a specified range photographing mode inwhich a size of the photographic range at a subject position is fixed ata predetermined size; a focal length calculating unit that calculates afocal length at which the subject within the photographic range isprojected almost over the entirety of the image-capturing area when thespecified range photographing mode is set, based upon (a) a plurality offocal lengths assumed by the zoom lens, (b) subject distances detectedin correspondence to the plurality of focal lengths when a referenceimage at the predetermined size is projected almost over the entirety ofthe image-capturing area and (c) the distance to the subject detectedwhen an image of the subject is captured; and a zoom control unit thatcontrols the zoom changing unit so as to match the focal length of thezoom lens with the focal length calculated at the focal lengthcalculating unit.

[0040] Another electronic camera according to the present inventioncomprises: a mode setting unit operated to set a specified rangephotographic mode in which a size of a photographic range at the subjectposition is fixed to a predetermined size; an image-capturing unit thatexecutes photoelectric conversion for a subject projected onto animage-capturing area by a photographic optical system; an electroniczoom unit that electronically enlarges a part of a subject imageachieved based upon image information provided by the image-capturingunit; and an electronic zoom control unit that controls the electroniczoom unit so as to enlarge an image corresponding to the photographicrange in the subject image to a size matching a size of the subjectimage.

[0041] A camera system according to the present invention comprises: azoom changing unit that changes a focal length of a zoom lens; animage-capturing unit that executes photoelectric conversion for an imageof a subject projected by the zoom lens onto an image-capturing area; arange finding unit that detects a distance to a subject; a mode settingunit operated to set a specified range photographing mode in which asize of the photographic range at a subject position is fixed at apredetermined size; and a zoom control unit that controls the zoomchanging unit based upon the photographic range and the subject distancewhen the specified range photographing mode is set so that the subjectwithin the photographic range is projected almost over the entirety ofthe image-capturing area; and a printing device that prints an imagephotographed in the specified range photographing mode in a sizesubstantially matching the predetermined size.

[0042] A computer-readable computer program product according to thepresent invention contains a control program for image data printcontrol. The control program for image data print control comprises: aninstruction for obtaining subject image data which is obtained bycapturing an image of the subject formed through a photographic opticalsystem output by an image-capturing element having a plurality ofpixels; an instruction for obtaining a distance to the subject; aninstruction for obtaining a number of pixels provided at theimage-capturing element; an instruction for obtaining a pixel pitch atthe image-capturing element; an instruction for obtaining a focal lengthof the photographic optical system; and an instruction for calculating aprinting resolution so as to print the subject image in a size equal toa size of the subject by using the subject image data, based upon thedistance to the subject, the number of pixels at the image-capturingelement, the pixel pitch at the image-capturing element and the focallength of the photographic optical system.

[0043] It is preferred that: this computer-readable computer programproduct is a recording medium in which the control program for imagedata print control is recorded; or the computer-readable computerprogram product is a carrier wave in which the control program for imagedata print control is embodied as a data signal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044]FIGS. 1A and 1B show an electronic camera according to the presentinvention achieved in an embodiment, with FIG. 1A presenting a plan viewof the electronic camera and FIG. 1B presenting a rear view of theelectronic camera;

[0045]FIG. 2 is a circuits block diagram of the electronic camera shownin FIG. 1;

[0046]FIG. 3 presents a schematic block diagram of a camera system;

[0047]FIG. 4 shows the procedures taken to execute the photographingthrough printing operations in the camera system shown in FIG. 3;

[0048]FIG. 5 presents a detailed flowchart of the procedurecorresponding to steps S101 through S103 in FIG. 4;

[0049]FIG. 6 presents a flowchart of the processing procedure continuingfrom the procedure in FIG. 5;

[0050]FIG. 7 illustrates the relationship between the subject and theCCD 214;

[0051]FIG. 8 shows the rectangular frame WA4 brought up on the displayLCD 3;

[0052] FIGS. 9A˜9C show rectangular frames brought up on the display LCD3, with FIG. 9A illustrating the change occurring in the rectangularframe WA4, FIG. 9B showing the rectangular frame WB5 and FIG. 9C showingthe rectangular frames WA4 and WB5;

[0053]FIGS. 10A and 10B illustrate the rectangular frame R in variation1, with FIG. 10A illustrating the relationship between the rectangularframe R and the areas S1˜S3 and FIG. 10B showing a display that includesthe mark 37 a;

[0054]FIG. 11A illustrates the rectangular frame R in the display thatincludes the mark 37 b and FIG. 11B shows the display that includes themark 37 c;

[0055] FIGS. 12A˜12D illustrate the rectangular frames R1 R3 invariation 2, with FIG. 12A illustrating the relationship among therectangular frames R1˜R3, FIG. 12B showing the rectangular frame R1 ondisplay, FIG. 12C showing the rectangular frame R2 on display and FIG.12D showing the rectangular frame R3 on display;

[0056]FIG. 13 is provided to facilitate an explanation of variation 3which is an example of a variation of the procedure in the flowchart inFIG. 5;

[0057]FIGS. 14A and 14B show the relationship between the printing-sizeS and the photographic range W, with FIG. 14A showing the printing sizeS set laterally longer and FIG. 14B showing the printing size S setlongitudinally longer;

[0058]FIG. 15 presents a flowchart provided to facilitate an explanationof the procedure implemented in the calibration mode in a secondembodiment;

[0059]FIGS. 16A and 16B show the relationships between the referencechart and the rectangular frames brought up on the display LCD 3, withFIG. 16A showing the frame 41 and the rectangular frame WA4 and FIG. 16Bshowing the frame 42 and the rectangular frame WA4;

[0060]FIG. 17 shows the procedure of the operations from photographingthrough printing, executed in the camera system in a third embodiment;

[0061]FIG. 18 presents a detailed flowchart of the procedurecorresponding to steps S101 through S103 in FIG. 17;

[0062]FIG. 19 presents a flowchart of the procedure continuing from FIG.18;

[0063]FIG. 20 shows the relationship between the photographic range Wand the image-capturing surface of the CCD 214;

[0064] FIGS. 21A˜21C show subject images displayed at the display LCD 3,with FIG. 21A showing an image obtained by setting f to fmax, FIG. 21Bshowing an image obtained by enlarging the image in FIG. 21A by amagnification factor of Mmax through electronic zoom and FIG. 21Cshowing an image obtained by enlarging the image in FIG. 21A by amagnification factor of (f0/fmax) through electronic zoom;

[0065]FIG. 22 shows the relationship between the photographic range 31and the display LCD 3 which is achieved when f=fmin;

[0066]FIG. 23 presents a flowchart of the control procedure achieved inVariation Example 1;

[0067]FIG. 24 presents a flowchart of the control procedure achieved inVariation Example 2;

[0068]FIG. 25 shows the relationship between the photographic range Wand the CCD 214 achieved in a fourth embodiment;

[0069]FIG. 26 presents a flowchart of the calibration procedure; and

[0070]FIG. 27 illustrates how the program may be provided through arecording medium or a data signal on the Internet or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] The following is an explanation of the embodiments of the presentinvention

[0072] First Embodiment

[0073]FIGS. 1A and 1B show the electronic camera according to thepresent invention achieved in an embodiment, with FIG. 1A presenting aplan view of the electronic camera and FIG. 1B presenting a rear view ofthe camera. As shown in FIG. 1A, at the upper surface of an electroniccamera 1, a main switch 4 through which a power on/off operation isperformed, a shutter release button 5, a dial (command dial) 6 operatedto select a recording mode or a reproduction mode and a display panel 7on which camera information is displayed are provided. The recordingmode in this context refers to a mode that allows a subject image to bephotographed and the image data to be recorded, whereas the reproductionmode refers to a mode in which the recorded image data are read out andare reproduced and displayed on a display LCD 3 (see FIG. 1B) providedat the rear surface of the camera.

[0074] In addition, at the rear surface of the camera, a viewfindereyepiece window 8, zoom switching buttons 9 operated to zoom aphotographic optical system 2 and various operating buttons are providedin addition to the display LCD 3 provided for image display, as shown inFIG. 1B. When the zoom switching button 9 is pressed at the W side, thephotographic optical system 2 is driven toward the wide angle side andwhen the zoom switching button 9 is pressed at the T side, thephotographic optical system 2 is driven toward the telephoto side. Inthe recording mode, subject images captured by a CCD 214 which is to bedetailed later are sequentially displayed on the display LCD 3, whereasa thumbnail display of images stored in a memory card 424 to be detailedlater or a display of an individual reproduced image is brought up onthe display LCD 3 when the reproduction mode is selected.

[0075] Reference numeral 10 indicates a menu button operated to displaya setting menu, and while the setting menu is on display, items to beset are selected through selector buttons 11 a˜11 d to make varioussettings. When setting the printing size, as explained later, thebuttons 10 and 11 a˜11 d are operated to bring up a printing sizesetting menu on the display LCD 3 to select a desired size from aplurality of printing sizes on display by operating the selector buttons11 a˜11 d. In the electronic camera 1 in the embodiment, a specifiedmagnification factor photographing mode which is to be detailed laterand a standard photographing mode which is equivalent to the recordingmode in electronic cameras in the related art can be selected. Either ofthese modes can be selected through a mode selector button 12. Theindividual modes are to be explained in detail later.

[0076] Reference numeral 13 indicates a focus mode button operated toswitch from one focus mode to another focus mode. In the embodiment, oneof three focus modes, i.e., a normal AF mode which is suited to snapshotphotographing operations, portrait photographing operations and thelike, a macro mode which is suited to photographing a subject set inextremely close proximity to the camera and an infinity mode (or adistant view mode) which is suited to photographing distant views oflandscapes, buildings and the like, can be selected. Each time the focusmode button 13 is pressed, one of the three focus modes described aboveis cyclically selected.

[0077]FIG. 2 is a circuit block diagram of the electronic camera shownin FIG. 1. In a ROM 443, a control program of the electronic camera 1 isstored. By turning on the main switch 4, power to the electronic camera1 is turned on and the control program is started up by a CPU 439. Asthe recording mode is selected through the dial 6, the electronic camera1 enters a photographing-enabled state. If, on the other hand, thereproduction mode is selected through the dial 6, an image can bedisplayed on the display LCD 3 by reproducing image data recorded in thememory card 424 which is a recording medium. It is to be noted that animage is displayed on the display LCD 3 based upon image-capturingsignals provided by the CCD 214 in the recording mode.

[0078] The photographic optical system 2 includes a plurality of lenses201˜204 and a focal adjustment operation is performed by a lens drivecircuit 430. While the focal adjustment operation by the lens drivecircuit 430 is normally executed in response to a command issued by theCPU 439, a focal adjustment operation can also be performed in responseto an operation signal which is output when a range ring 462 is manuallyoperated.

[0079] A shutter plate 208 and an aperture 215 are provided between thelens 203 and the lens 204 at the photographic optical system 2. Subjectlight having entered the photographic optical system 2 passes throughthe lenses 201˜204, the shutter plate 208 and the aperture plate 5, andan image is formed on the image-capturing surface of the CCD 214. Theaperture plate 215 and the shutter plate 208 each formed in a disk shapeare respectively driven by step motors 415 and 408 provided at thecenters of rotation of the disks. At the aperture plate 215, a pluralityof aperture openings (not shown) with varying opening areas areprovided, and a given aperture opening is set on the optical axis byrotating the aperture plate 215 with the step motor 415.

[0080] A full light-blocking portion (not shown) that blocks all thelight flux having passed through the lens 203 and an opening (not shown)that allows the entire light flux to pass through are provided at theshutter plate 208. During an exposure operation, the opening of theshutter plate 208 is set on the optical path and as the exposureoperation ends, of the full light-blocking portion is set on the opticalpath. Drive control is implemented on the step motor 415 which rotatesthe aperture plate 215 by a drive circuit 453. The drive all of the stepmotor 408 which rotates the shutter plate 208 is controlled by a shutterdrive circuit 454.

[0081] During a photographing operation, the electric charges havingbeen stored at the CCD 214 are first swept out and a specific opening atthe aperture plate 215 is set on the optical path. Then, after anexposure operation is performed at the CCD 214 over a predeterminedlength of time, electric charges are stored at the CCD 214 again. Thelength of the exposure period corresponds to the length of time thatelapses after the electric charges are swept out until the optical pathbecomes blocked by the full light-blocking portion of the shutter plate208 again.

[0082] When the subject image is formed on the image-capturing surfaceof the CCD 214 by the photographic optical system 2, a signal electriccharge, which corresponds to the intensity level of the subject imagelight is stored. The CCD 214 is provided with a horizontal drive signalfrom a digital signal processor (hereafter referred to as a DSP) 433 anda vertical drive signal from a CCD drive circuit 434 which is controlledby the DSP 433. In other words, the operational timing of the CCD 214 iscontrolled by the DSP 433 and the CCD drive circuit 434 and signals fromthe CCD 214 are input to an image processing unit 431.

[0083] The image processing unit 431, which includes a noise removalcircuit and a DC reproduction circuit, implements analog processing suchas noise removal and gain control on the image signals output from theCCD 214. The analog image signals output from the image processing unit431 are converted to digital signals at an analog/digital conversioncircuit (hereafter referred to as an A/D conversion circuit) 432. Thedigital image data resulting from the conversion are input to the DSP433 mentioned earlier.

[0084] At the DSP 433, image processing such as edge compensation, gammacorrection and white balance adjustment is performed on the image dataoutput from the A/D conversion circuit 432. In addition, the DSP 433temporarily stores the image data having undergone various types ofimage processing into a buffer memory 436 by controlling a data busconnected to the buffer memory 436 and the memory card 424.Subsequently, the image data read out from the buffer memory 436 undergodata compression in a predetermined compression format (e.g., the JPEGformat) and the compressed data are recorded into the memory card 424.

[0085] In addition, the DSP 433 stores the image data obtained byimplementing the image processing described above on the image dataresulting from the image-capturing operation at the CCD 214 and imagedata obtained by decompressing the image data read out from the memorycard 424 in a frame memory 435, and displays images based upon theseimage data at the display LCD 3 provided at the electronic camera 1. TheDSP 433 also performs timing management in data input/output whenrecording the image data into the memory card 424 or recording thedecompressed photographic image data into the buffer memory 436.

[0086] The buffer memory 436, in which the image data obtained basedupon the output from the CCD 214 are temporarily stored, is utilized toreduce the extent of inconsistency in the speed with which image dataare input to/output from the memory card 424 and to reduce thedifference among the varying processing speeds of the CPU 439, the DSP433 and the like. A timer 445 which is internally provided with a clockcircuit outputs time data indicating the current time point to the CPU439 and is also utilized as a timer in monitor on/off control which isto be detailed later. The time data are recorded together with the imagedata explained above into the memory card 424.

[0087] A colorimetering element 417 detects the color temperature of amain subject and its surrounding area and outputs data indicating thedetected color temperature to a colorimetering circuit 452. Thecolorimetering circuit 452 implements a specific type of processing onthe analog signal output from the colorimetering element 417 to convertthem to digital values and outputs the digital signal resulting from theconversion to the CPU 439. An interface 448 is provided so as to allow aspecific external apparatus (not shown) to be connected and to enabledata exchange between the CPU 439 and the external apparatus connectedthereto. Reference numeral 440 indicates a display circuit that controlsthe display panel 7 to display the details of settings made for thephotographing operation on the display panel 7. It is to be noted thatthe printing size, which is to be explained in detail later, isdisplayed on the display LCD 3 or the display panel 7.

[0088] Next, the operations performed in the electronic camera 1 areexplained. As mentioned earlier, either the recording mode or thereproduction mode can be selected through the dial 6 in the electroniccamera 1. The recording mode includes a standard photographing modewhich is equivalent to the recording mode in electronic cameras in therelated art and a specified magnification factor photographing mode. Ifa photographing operation is performed in the specified magnificationfactor photographing mode, a printing resolution which will allow thephotographed subject image to be printed at the magnification factorthat has been set is automatically calculated and this printingresolution is recorded into the memory card 424 together with the imageinformation. By printing the subject image at the printing resolutionrecorded in the memory card 424, the subject image magnified at thespecific magnification factor is printed.

[0089] (Standard Photographing Mode)

[0090] First, the operation performed in the standard photographing modewhich is similar to the operation of electronic cameras in the relatedart is explained. The dial 6 is operated to select the recording mode orthe reproduction mode. The main switch 4 is turned on after setting therecording mode at the dial 6 or the recording mode is set at the dial 6after turning on the main switch 4 to enable a photographing operation.Image signals output from the CCD 214 first undergo analog processingsuch as noise removal and gain control at the image processing unit 431and then are converted to digital signals at the A/D conversion circuit432. The digitized signals are provided to the DSP 433 where theyundergo image preprocessing such as edge compensation and gammacorrection before they are temporarily stored into the buffer memory436.

[0091] Subsequently, the image data are exchanged between the CPU 439and the buffer memory 436, a white balance adjustment value isascertained by using the image data and a white balance adjustment isexecuted at the DSP 433 based upon the adjustment value. The image datahaving undergone the white balance adjustment are stored into the buffermemory 436 again. The image data stored in the buffer memory 436 areprocessed at the DSP 433 to prepare image data to be displayed on thedisplay LCD 3. The processed image data are written into the framememory 435 and are displayed on the display LCD 3 as a photographicmonitor image referred to as a through image. This through image issequentially updated over predetermined time intervals based upon thesubject light entering the photographic optical system 2 as theoperation described above is executed repeatedly.

[0092] As the shutter release button 5 is pressed halfway down and ahalfway press switch (not shown) is turned on in response, the focaladjustment state of the photographic optical system 2 is detected basedupon the contrast of the image data. Namely, the focal adjustmentoperation is performed by the lens drive circuit 430 so as to form afocused subject image on the CCD 214 based upon the contrast in theimage data. In addition, when the shutter release button 5 is pressedhalfway down, the CPU 439 detects the brightness level of the subjectfrom the image data and performs an exposure calculation based upon thedetected brightness level.

[0093] It is to be noted that the focal adjustment operation in theelectronic camera 1 can be performed in a mode referred to as a“continuous AF mode” or a mode referred to as a “single AF mode”. In thecontinuous AF mode, the focal adjustment operation is repeatedlyexecuted regardless of whether or not the shutter release button 5 isoperated and a focus lock is effected as the shutter release button 5 ispressed halfway down. In the single AF mode, on the other hand, thefocal adjustment operation is performed only when the shutter releasebutton 5 is pressed halfway down and then also a focus lock is effected.

[0094] As the shutter release button 5 is pressed all the way down afterthe shutter release button 5 is first pressed halfway down, a full pressswitch (not shown) is turned on. As a result, the signal charges storedat the CCD 214 are first swept out and then the shutter plate 208 andthe aperture plate 215 are driven based upon the results of the exposurecalculation to capture an image at the CCD 214.

[0095] The image signal output from the CCD 214 through thisimage-capturing operation first undergo the series of processingexplained earlier before it is stored into the buffer memory 436. Theimage data stored in the buffer memory 436 are written into the framememory 435 after undergoing the processing at the DSP 433 to be preparedas a image data for display at the display LCD 3 and a photographicimage referred to as a freeze image is displayed on the display LCD 3.The image data obtained through such image preprocessing then undergodata compression at the DSP 433, the compressed data are assigned with aspecific data name by the CPU 439 and the data are then recordedtogether with the time information provided by the timer 445 into thememory card 424 constituting a recording medium (a PC card, a CF card orthe like) which may be a flash memory.

[0096] A zoom signal generated in response to an operation of a zoomswitching button 9 and a halfway press operation signal and a full pressoperation signal generated in response to an operation of the shutterrelease button 5 are input to the CPU 439. When the zoom switchingbutton 9 is operated toward the telephoto side (T), the CPU 439 drivesthe lens drive circuit 430 to optically increase the zoom magnificationfactor. If, on the other hand, the zoom switching button 9 is operatedtoward the wide-angle side (W), the zoom magnification factor islowered.

[0097] (Specified Magnification Factor Photographing Mode)

[0098] Next, an explanation is given on the specified magnificationfactor photographing mode. A plurality of printing magnification factorsM are stored in advance at the ROM 443 in FIG. 2 and a specific printingmagnification factor M for the subject image is set by using the menubutton 10 and the selector buttons 11 a˜11 d explained earlier in theelectronic camera 1 in the embodiment. For instance, if magnificationfactors of 1, 2 and 3 are stored as the printing magnification factorsM, a printing magnification factor setting menu is first brought up atthe display LCD 3 by operating the menu button 10. In the printingmagnification factor setting menu, the individual magnification factorsare listed, and by selecting one of the magnification factors with theselector buttons 11 a˜11 d, the printing magnification factor M is setto the selected value.

[0099] While a detailed explanation is to be given later, if theprinting magnification factor M is set to 2, for instance, a printingresolution that will allow the image to be printed twice as large as theactual size is calculated. In addition, a plurality of printing sizesare stored in the ROM 443, and one of these printing sizes can beselected in advance with, for instance, the menu button 10 and theselector buttons 11 a˜11 d.

[0100]FIG. 3 illustrates a schematic structure that may be adopted in acamera system capable of performing operations from photographing thesubject through printing the image at a magnification factor of 1. Imagedata obtained by performing a photographing operation in the electroniccamera 1 are taken into a personal computer 20 via the memory card 424that can be detachably mounted at the camera 1. Alternatively, the imagedata may be transferred to the personal computer 20 from the camera 1via a communication cable 21, or the image data may be transferred tothe personal computer 20 wirelessly or via an Internet line. A displaymonitor 22 and a printer 23 are connected to the personal computer 20. Adriver software program for driving the printer 23 is pre-installed inthe personal computer 20 so that the resolution and the printing size ofthe image to be printed can be set freely. It is to be noted that theimage data may be directly input to the printer 23 instead of firsttaking the image data into the personal computer 20.

[0101]FIG. 4 presents a schematic flowchart of the procedures of theoperations from photographing through printing executed in the camerasystem shown in FIG. 3. In FIG. 4, the processing from step S101 throughstep S103 is a photographing procedure implemented in the camera 1, andthe processing from step S104 through step S106 is the printing-relatedprocedure. In step S101, the mode selector button 12 is operated toswitch from the standard photographing mode to the specifiedmagnification factor photographing mode. The printing magnificationfactor M may be displayed on the display LCD 3 or the display panel 7when the specified magnification factor photographing mode is set. Instep S102, a photographing operation is performed in the camera in thespecified magnification factor photographing mode. In step S103, headerinformation that includes the printing resolution (to be detailed later)and the image data are recorded into the memory card 424.

[0102] In step S104, the header information and the image data in thecamera 1 are read into the personal computer 20 by, for instance, firstremoving the memory card 424 from the camera 1 and then installing thememory card 424 into the personal computer 20 in FIG. 3. In step S105,image processing is performed in conformance to the printing resolutionincluded in the header information. In step S106, the image is printedat the magnification factor M by the printer 23.

[0103] It is assumed with regard to the printing size mentioned abovethat all the printing sizes stored in the ROM 443 are in a selectedstate at the initial stage. The photographer is allowed to set thedesired printing size in a selected state as necessary. The followingexplanation is given on the assumption that the standard paper sizes,i.e., A4, B4, A5 and B6 sizes, are stored in advance in the ROM 443 atthe printing sizes and that all the sizes are currently in a selectedstate.

[0104] Next, the procedure of the processing from step S101 through stepS103 in FIG. 4 executed at the camera is explained in further detail inreference to the flowchart presented in FIGS. 5 and 6. FIGS. 5 and 6present a flowchart of the processing procedure of a program executed bythe CPU 439 of the camera 1. In step S201, a decision is made as towhether or not the mode selector button 12 has been operated to switchto the specified magnification factor photographing mode. If it isdecided in step S201 that the specified magnification factorphotographing mode has been selected, the operation proceeds to stepS202. If, on the other hand, it is decided in step S201 that thespecified magnification factor photographing mode has not been selected,i.e., if it is decided that the standard photographing mode is currentlyset, the operation proceeds to step S206 to execute a sequence ofprocessing in the standard photographing mode.

[0105] In step S202, the depth of field is reduced by opening theaperture so as to measure the subject distance with a higher degree ofaccuracy. In step S203, the photographic optical system 2 is adjustedinto a macro state. Since the subject image is printed at amagnification factor of 1 or in an enlargement in the specifiedmagnification factor photographing mode, the photographing operation isnormally performed with the camera set in close range to the subject.For this reason, control is implemented to automatically set a macrorange in step S203. In step S204, the position of the photographicoptical system 2 is adjusted so as to set it at a predeterminedrecommended zoom position. To set the photographic optical system 2 at arecommended zoom position, the lenses should be moved to, for instance,a position halfway between the telephoto end and the zoom end so as tominimize the lens aberration.

[0106] In step S205, a decision is made as to whether or not the macromode has been cleared. If it is decided that the macro mode has not beencleared, the operation proceeds to step S207, whereas if it is decidedthat the focus mode button 13 has been operated to clear the macro mode,the operation proceeds to step S206 to execute the standardphotographing mode processing. In step S207, a decision is made as towhether or not the shutter release button 5 has been pressed halfwaydown, and the operation proceeds to step S208 if it is decided that theshutter release button 5 has been pressed halfway down, whereas theoperation returns to step S201 if it is decided that the shutter releasebutton 5 has not been pressed halfway down.

[0107] In step S208, the selected printing magnification factor is readfrom the ROM 443. In step S209, the focal adjustment operation isexecuted for the photographic optical system 2 by the lens drive circuit430, and once the current distance to the subject is calculated, theoperation proceeds to step S210 to read the focal length.

[0108]FIG. 7 shows the relationship between the subject and the CCD 214.A subject image inside a photographic range W is projected over theentire image-capturing area at the CCD 214. It is to be noted that thecode W representing the photographic range in FIG. 7 indicates thedimensions of the long side of the photographic range at the subjectposition, i.e., the lateral measurement of the photographic range whenthe camera 1 in FIG. 1 is held in a normal position, with N in FIG. 7indicating the number of pixels provided at the CCD 214 along thewidthwise direction in the image-capturing area. In addition, Pindicates the pixel pitch at the CCD 214. The relationship expressed asin expression (1) below is achieved at all times among the focal lengthf, the distance f′ between the photographic optical system 2 and theimage-capturing surface and the subject distance L.

1/L+1/f′=1/f f′=L·f/(L−f)  (1)

[0109] A decision is made in step S211 in FIG. 5 as to whether or notthe subject image over the photographic range W shown in FIG. 7 can beprinted on an A4-size sheet at the selected printing magnificationfactor M. If an affirmative decision (YES) is made in step S211, theoperation proceeds to step S212, whereas if a negative decision (NO) ismade, the operation proceeds to step S217. If a negative decision (NO)is made in step S211 and the operation proceeds to step S217 as aresult, a rectangular frame WA4 indicating the maximum range that can beprinted on an A4-size sheet at the printing magnification factor M isdisplayed over the subject image 30 on the display LCD 3 as shown inFIG. 8.

[0110] In the following step S218, a warning is issued to notify thatthe photographic range W cannot be printed on an A4-size sheet. Thiswarning may be issued by flashing an “A4” mark 31 indicating theprinting size on the display LCD 3 as shown in FIG. 8 or it may beprovided as a voice message by mounting a speaker at the electroniccamera. The rectangular frame WA4 on display makes it possible toroughly ascertain how much closer to the subject the camera needs to bemoved to allow the subject image to be printed on an A4-size sheet.

[0111] If the operation proceeds from step S211 to step S212, a decisionis made in step S212 as to whether or not the subject image over thephotographic range W can be printed on a B5-size sheet at the printingmagnification factor M. If a negative decision (NO) is made in stepS212, the operation proceeds to step S214, whereas if an affirmativedecision (YES) is made, the operation proceeds to step S213. In stepS214, a rectangular frame corresponding to B5 size is brought up ondisplay together with the subject image at the display LCD 3. At thistime, the subject image over the photographic range W which is equal toor smaller than A4 size and larger than B5 size is displayed on thedisplay LCD 3.

[0112] If, on the other hand, the operation proceeds from step S212 tostep S213, a decision is made in step S213 as to whether or not thesubject image over the photographic range W can be printed on an A5-sizesheet at the printing magnification factor M. If an affirmative decision(YES) is made in step S213, the operation proceeds to step S215 todisplay a rectangular frame corresponding to B6 size together with thesubject image at the display LCD 3. At this time, the subject image overthe photographic range W which is equal to or smaller than A5-size isdisplayed on the display LCD 3.

[0113] If, on the other hand, a negative decision (NO) in step S213, theoperation proceeds to step S216 to display a rectangular framecorresponding to A5-size together with the subject image at the displayLCD 3. At this time, the subject image over the photographic range Wwhich is equal to or smaller than B5 size and larger than A5-size isdisplayed on the display LCD 3. In step S219, a decision is made as towhether or not the shutter release button 5 has been pressed all the waydown, and if it is decided that the shutter release button 5 has beenpressed all the way down, the operation proceeds to step S220 in FIG. 6.Otherwise, the operation returns to step S209.

[0114] It is to be noted that a zooming operation may be performedeither automatically or manually so as to roughly match the photographicrange W to the rectangular frame WA4 on display before pressing theshutter release button 5 all the way down. An automatic zoomingoperation may be performed after, for instance, the subject distance Lhas been sustained at a constant value over a predetermined length oftime or longer. If the subject distance L changes after the zoomingoperation, the photographic optical system 2 is reset to the recommendedzoom position.

[0115] If it is decided in step S219 that the shutter release button 5has not been pressed all the way down, the processing in steps S209through S 219 is executed repeatedly. In this case, the photographicrange W changes if the photographer moves closer to or further away fromthe subject, and in response, the size of the rectangular frame WA4displayed on the display LCD 3, too, changes continuously. For instance,if the photographer moves closer to the subject from the distance shownin FIG. 8, the rectangular frame WA4 indicating A4 size becomes larger,as shown in FIG. 9A. If the photographer moves even closer to thesubject and the range achieved by enlarging the photographic range W bythe factor M becomes smaller than the printing size, i.e., A4 size, theoperation sequentially proceeds to step S212 and step S214 from stepS211 in FIG. 5. At this time, a rectangular frame WB5 indicating B5 sizeand a mark 32 indicating that the rectangular frame WB5 matches B5 sizeare brought up on display at the display LCD 3 as shown in FIG. 9B.

[0116] It is to be noted that in steps S214, S215, S216 and S217 in FIG.5, the largest printing size that can be contained in the range achievedby enlarging the photographic range W by the factor M is displayed onthe display LCD 3. For instance, since the range achieved by enlargingthe photographic range W by the factor M is larger than B5 size andequal to or smaller than A4 size, the largest rectangular WB5 matchingB5 size (see FIG. 9B) among the B5-size rectangular frame, the A5-sizerectangular frame and the B6-size rectangular frame that can bedisplayed is displayed in step S214 in the embodiment. However, insteadof displaying the largest rectangular frame alone, the two largestrectangular frames WB5 and WA5 may be displayed as shown in FIG. 9C. Insuch a case, “B5” and “A5” marks 32 indicating the sizes of therectangular frames WB5 and WA5 are brought up on display. In addition, acenter mark C indicating the center of the display LCD 3 may bedisplayed as shown in FIG. 9B to facilitate positioning of the subjectat the center of the rectangular frame WB5.

[0117] In step S220 in FIG. 6, the image captured at the CCD 214 istaken in. In step S221, a printing resolution k, which will allow thesubject image over the photographic range W to be printed at themagnification factor M, is calculated. The printing range W shown inFIG. 7 can be expressed as in expression (2) below using the number ofpixels N, the pitch P, the subject distance L and the distance f′calculated through the formula in expression (1). Since N pixelscorrespond to an area ranging over the dimensions M·W when the subjectover the photographic range W is to be printed at the printingmagnification factor M, the printing resolution k may be set asexpressed in expression (3) below. A modification of expression (3),obtained by using expression (2), is expressed in expression (4) below.

W=N·P·L/f′  (2)

k=N/(M·W)  (3)

=f′/(P·L·M)  (4)

[0118] The errors attributable to the lenses constituting thephotographic optical system 2 should be taken into consideration inreality, and thus, the printing resolution k can be expressed as inexpression (5) below by using an error coefficient α.

k=α·f′/(P·L·M)  (5)

[0119] The image data are compressed in a specific format in step S222in FIG. 6. In step S223, the focal length f, the subject distance L, thenumber of pixels N, the pixel pitch P, the specified printingmagnification factor M, the printing resolution k and the like arerecorded as tag information together with the compressed image data intothe memory card 424. Thus, the sequence of processing from photographingthrough recording executed at the electronic camera 1 ends. The imagedata corresponding to the entire image captured by the CCD 214 may berecorded in the memory card 424, or only the image data over the rangeenclosed by the largest rectangular frame among the rectangular framescorresponding to the printing sizes displayed on the display LCD 3 maybe clipped out and stored in the memory card 424.

[0120] It is to be noted that if the printing resolution k is to berecorded in the TIFF format, the printing resolution k is recorded inunits corresponding to the resolution along the width of the image, theresolution along the height of the image and the resolution along thewidth and the height of the image respectively defined by tag numbers282˜284. If, on the other hand, the printing resolution k is recorded inthe Exif format, individual pieces of information indicating the subjectdistance, the lens focal length, the resolution along the height of thefocal plane, the resolution along the width of the focal plane and theresolution over the focal plane as defined by tag numbers 37386, 37382,41486˜41488 are recorded. Since a free area, which allows the user towrite data freely, is provided in such a case, the printingmagnification factor M may be written into the free area to enable theprinter to read the data to calculate the printing resolution k with theapplication software program.

[0121] In addition, if a type of camera that records data in anotherfile format in the standard photographing mode is used, the format maybe switched to the TIFF format or the Exif format when the specifiedmagnification factor photographing mode is selected.

[0122] When printing the subject image, the image data are taken intothe personal computer 20 shown in FIG. 3 as described above and theimage is printed on the printer 23 connected to the personal computer20. During this process, the printer 23 reads the printing resolution krecorded as tag information and sets the printing resolution k as theresolution at which the image is to be printed. Namely, through aprinting operation performed at the printing resolution k, the printedsubject image is magnified by a factor M as desired. It is to be notedthat if the application software program in use does not automaticallyread and set the printing resolution k, the user must check the taginformation and manually set the printing resolution k.

[0123] (Variation 1)

[0124] In the embodiment described above, the size of the rectangularframe WA4 displayed on the display LCD 3 continuously changes as shownin FIG. 9A as the photographer changes the subject distance L. In thefirst example of variation explained below, a rectangular frame R with afixed size is displayed as shown in FIG. 10A. First, the display area ofthe display LCD 3 is divided into three areas S1, S2 and S3. The area S1ranges on the inside of a rectangular border 35. The area S2 is enclosedby a rectangular border 34 and the border 35. The area S3 is enclosed bythe display frame of the display LCD 3 and the border 34. Therectangular frame R on display is set roughly halfway between the border34 and the border 35.

[0125] As shown in FIG. 10B, if the rectangular frame WA4 mentionedearlier is contained within the area S1, the rectangular frame R and a“>A4” mark 37 a are brought up on display. This display enables thephotographer to verify that the range indicated by the rectangular frameR is larger than A4 size. It is to be noted that while the rectangularframe WA4 is shown on the display LCD 3 to in FIG. 10B facilitate theexplanation, the rectangular frame WA4 is not displayed in reality.

[0126] If the subject distance changes so that the rectangular frame WA4is now contained inside the area S2, as shown in FIG. 11A, therectangular frame R and a “=A4” mark 37 b are brought up on display,since the range indicated by the rectangular frame R is roughly equal toA4 size. If the rectangular frame WA4 is contained within the area S3 asshown in FIG. 11B, the rectangular frame R and a “<A4” mark 37 c arebrought up on display since the range indicated by the rectangular frameR is smaller than A4 size.

[0127] If the photographic range W is further reduced and the operationproceeds from step S212 to step S214 accordingly, a “>B5” markcorresponding to B5 size is brought out on display in place of the mark37 a shown in FIG. 10B. As described above, the rectangular frame R witha fixed size is displayed even as the photographic range W changes andby displaying one of the marks 37 a˜37 c to indicate the size of therectangular frame R relative to the printing size, an approximate sizeof the range indicated by the rectangular frame R relative to theprinting size can be ascertained. In particular, since the size of therectangular frame R remains unchanged, the display control can begreatly simplified compared to the control implemented when the size ofthe rectangular frame continuously changes.

[0128] In addition, the display magnification factor HM representing theratio of the size of the subject image displayed on the display LCD 3and the actual size of the image may be displayed on the display LCD 3as shown in FIG. 10A. With Lw representing the size of the displayscreen of the display LCD 3, the display magnification factor HM can becalculated through expression (6) below by using expression (3).

HM=Lw/M·W=Lw/(N/k)  (6)

[0129] (Variation 2)

[0130] While the size of the rectangular frame R remains constant invariation 1, the size of the rectangular frame R in variation 2 isvaried over three levels, i.e., R1, R2 and R3. As shown in FIG. 12A,three rectangular frames R1, R2 and R3 with the varying sizes can bedisplayed on the display LCD 3. For instance, if the rectangular frameWA4 mentioned earlier corresponds to the photographic range shown inFIG. 12B, the rectangular frame R1, which is the closest in size to therectangular frame WA4, is brought up on display. As in variation 1, oneof the “>A4”, “=A4” and “<A4” marks 37 a 37 c is displayed at this timein conformance to the relationship between the size of the rectangularframe R1 and the size of the rectangular frame WA4.

[0131] When the distance to the subject increases and the rectangularframe WA4 corresponds to the photographic range shown in FIG. 12C, therectangular frame R2 is brought up on display. In this case, one of the“>A4”, “=A4” and “<A4” marks 37 a˜37 c is displayed in conformance tothe relationship between the size of the rectangular frame R2 and thesize of the rectangular frame WA4. As the distance to the subjectfurther increases and the rectangular frame WA4 corresponds to thephotographic range shown in FIG. 12D, the rectangular frame R3 isbrought up on display. In this case, one of the “>A4”, “=A4” and “<A4”marks 37 a˜37 c is displayed in conformance to the relationship betweenthe size of the rectangular frame R3 and the rectangular frame WA4. Ifthe operation proceeds from step S212 to step S214 in FIG. 5, therectangular frames R1˜R3 correspond to B5 size, and accordingly, “>B5”,“=B5” and “<B5” marks are displayed instead of the marks 37 a˜37 ccorresponding to A4 size. Since the rectangular frame is displayed byvarying its size over three levels, i.e., R1˜R3, in variation 2, thephotographic range can be ascertained in finer increments than invariation 1.

[0132] (Variation 3)

[0133]FIG. 13 shows a variation of the processing in the flowchart inFIG. 5, which is achieved by eliminating step S202 and adding steps S301and S302 in the processing shown in FIG. 5. After moving the lens intothe micro area in step S203, the zoom position is set at the telephotoend in step S302. By setting the zoom position at the telephoto end inthis manner, an advantage is achieved in that the subject distance L canbe measured with a higher degree of accuracy. In addition, a decision ismade in step S302 as to whether or not the zoom position has beenchanged and if it has been changed, the processing is executed in thestandard photographing mode in step S206, whereas if the zoom positionhas remained unchanged, the processing in step S207 and subsequent stepsin FIG. 5 is executed.

[0134] It is to be noted that while the printing resolution k iscalculated through expression (4) or (5) in the embodiment explainedabove, a table of the printing resolutions k relative to variables,i.e., the subject distance L and the focal length f may be stored inadvance in the ROM 443 so as to allow the printing resolution k to beextracted from the table in correspondence to a given set of subjectdistance L and focal length f instead.

[0135] In addition, while the printing resolution k is calculated in theelectronic camera 1 in FIG. 3, the printing resolution k may be insteadcalculated in the personal computer 20 or the printer 23 on the printingside based upon the subject distance L, the focal length f, the numberof pixels N, the pixel pitch P and the printing magnification factor Mrecorded as the tag information. It is to be noted that if no printingmagnification factor M is recorded as tag data or a printingmagnification factor of 0 is recorded as tag data, it is assumed that nospecification has been made with regard to the printing magnificationfactor and, accordingly, the subject image is printed at themagnification factor of 1.

[0136] The first embodiment has been explained by assuming that theaspect ratio of the printing size and the aspect ratio at the CCD 214are equal to each other. However, if the aspect ratios of thephotographic range W and the printing size are different, e.g., if theprinting size S is laterally elongated compared to the photographicrange W as shown in FIG. 14A, the various parameters should becalculated by comparing the longitudinal dimensions of the photographicrange W and the printing size S to ensure that the entire image isprinted. If, on the other hand, the printing size S is longitudinallyelongated compared to the photographic range W as shown in FIG. 14B, thevarious parameters should be calculated by comparing the lateraldimensions of the photographic range W and the printing size S in asimilar manner. This principle applies to the following explanation, aswell.

[0137] An explanation is given above in reference to the firstembodiment on the assumption that the ratio “longitudinal measurement:lateral measurement” with regard to the printing sizes and the ratio“longitudinal measurement: lateral measurement” of the CCD 214 are equalto each other. However, if the aspect ratio of the photographic range Wis different from the aspect ratio of the printing size, e.g., if theprinting sizes is wider than the photographic range W as shown in FIG.14A, the sizes of the photographic range W and the printing sizes shouldbe compared against each other through a comparison of theirlongitudinal measurements. If, on the other hand, the printing sizes hasa greater height than the photographic range W as shown in FIG. 14B, thesizes of the photographic range W and the printing sizes should becompared against each other through a comparison of their lateralmeasurements. This principle applies to the following explanation aswell.

[0138] Furthermore, if the printing resolution k is above or below adesirable printing resolution range, the resolution may be lowered bysub-sampling or culling the image data or maybe raised throughinterpolation processing (e.g., through bi-cubic interpolationprocessing). For instance, when a photographic range with its longerside equaling approximately 50 cm is photographed by using the CCD 214with 2000 pixels provided along the longitudinal direction and anA4-size (with its longer side equaling approximately 30 cm) area of thephotographed image is printed at a magnification factor of 1, theprinting resolution is lowered to approximately 40 (dots/cm). In such acase, the printing resolution may be raised to 80 (dots/cm) throughinterpolation processing to reduce the appearance of jaggies. When aphotographic range having a longer side of approximately 5 cm isphotographed and the photographed image is printed at a magnificationfactor of 1, on the other hand, the printing resolution increases to anexcessively high level of 400 (dots/cm), and in such a case, the imagedata resolution may be reduced through image data sub-sampling orinterpolation processing so as to set the resolution to approximately150 (dots/cm).

[0139] In addition, if a wide converter or a tele-converter is mountedat the front surface of the photographic optical system 2 in theelectronic camera, information indicating that such a converter has beenmounted is either automatically or manually transmitted to the camera.In this case, the focal length f is corrected. The specifiedmagnification factor photographing mode may be disallowed or thespecified magnification factor photographing mode may be cleared in sucha situation, as well.

[0140] The following features are achieved in the first embodimentexplained above.

[0141] (a) Since the rectangular frame corresponding to the printingsize is displayed on the display LCD 3, a photographing operation can beperformed while checking the image to be printed.

[0142] (b) By setting the desired printing magnification factor M duringthe photographing operation, the printing resolution k corresponding tothe M-factor printing operation is automatically calculated and thus, aprinting operation can be performed at the calculated printingresolution k to print the image at the magnification factor M with ease.

[0143] Second Embodiment

[0144] In the first embodiment explained above, the printing resolutionk is calculated by using the expression (4) or the expression (5) whichincorporates the error coefficient α. However, since the errorcoefficient α varies among individual cameras, the errors of variouscameras cannot be corrected accurately by using a specific single errorcoefficient α. Accordingly, a method of correcting the error in eachcamera by photographing a reference chart with the camera is adopted inthe second embodiment. In the following explanation, such a correctionmode is referred to as a calibration mode, and the calibration operationto be detailed later is executed by, for instance, operating the dial 6in FIG. 1 to set the electronic camera in the calibration mode. In thecalibration mode, the printing magnification factor M is automaticallyset to M=1.

[0145]FIG. 15 presents a flowchart of the procedure implemented tocalibrate the lens error. It is to be noted that a reference chart whichincludes printed frames corresponding to specific printing sizes, e.g.,A4 size and B4 size, should be prepared in advance for the calibrationoperation. Once the calibration mode is set, the processing shown inFIG. 15 starts. In step S501, the position of the photographic opticalsystem 2 is adjusted at the macro position and also at the telephotoend.

[0146] The photographer holds the electronic camera 1 toward thereference chart with the photographic optical system 2 maintaining thestate set in step S501. Since the continuous AF mode for constantlyexecuting the focal adjustment operation is selected in conjunction withthe calibration mode, a focal adjustment is performed using thereference chart. In step S502, the rectangular frame WA4 correspondingto A4 size and a reference chart 40 are displayed on the display LCD 3as shown in FIG. 16A. The reference chart 40 includes a frame 41indicating A4 size and a frame 42 indicating B5 size, and, accordingly,FIG. 16A shows the frames 41 and 42 and the rectangular frame WA4brought up on display at the display LCD 3.

[0147] If the error coefficient α, which indicates the lens error asexplained earlier, is 1, the frame 41 and the rectangular frame WA4 onthe display LCD 3 will match. However, since they do not match in FIG.16A, the error coefficient α≠1. The photographer moves away from thereference chart 40 until the frame 41 matches the rectangular frame WA4and presses the shutter release button 5 all the way down when the frame41 becomes matched with the rectangular frame WA4. Once the shutterrelease button 5 is pressed all the way down, the operation proceedsfrom step S503 to step S504 in FIG. 15 to execute a focusing operation.

[0148] In step S505, a correction value β is calculated based upon thesubject distance L2 and the focal length f2 ascertained during thefocusing operation executed in step S504. A theoretical printingresolution k1 is determined through the expression (7) without allowingfor any lens error. A printing resolution k2 calculated by taking intoconsideration the error based upon the focal length f2 and the subjectdistance L2 obtained through the focusing operation, on the other hand,is expressed as in the expression (8) below, assuming thatf2′=L2˜f2/(L2−f2). The correction value β, which is represented as theratio of k1 and k2, can be calculated through the expression (9) below.In this embodiment, it is assumed that M=1 and that S matches the A4size.

k1=N/(printing size S)  (7)

k2=f2′/(P·L2·M)  (8)

β=k1/k2=P·L 2·M/(f 2′·S)  (9)

[0149] Next, the rectangular frame WB5 corresponding to B5 size and thereference chart 40 are brought up on display at the display LCD 3 asshown in FIG. 16B in step S506. The photographer moves further away fromthe reference chart 40 until the frame 42 matches the rectangular frameWB5, and when the frame 42 is matched with the rectangular frame WB5,the shutter release button 5 is pressed all the way down. Once theshutter release button 5 is pressed all the way down, the operationproceeds from step S507 to step S508 in FIG. 15 to execute a focusingoperation. A printing resolution k3 set at this time is calculatedthrough the expression (10) below by using the focal length f3 and thesubject distance L3 obtained through the focusing operation executed instep S508. It is assumed that f3′=L3−f3/(L3−f3). In step S509, acorrection value γ which represents the ratio of k1 and k3 iscalculated. The correction value γ is expressed as the expression (11)below. In step S510, an average α2 of the correction value β and thecorrection value γ is calculated through the expression (12) and thisaverage α2 is set as the correction coefficient in the secondembodiment.

k3=f3′/(P·L3·M)  (10)

γ=k1/k3=P·L3·M/(f 3′·S)  (11)

α2=(β+γ)/2  (12)

[0150] Since the correction coefficient α2 is set for each electroniccamera in the second embodiment, the lens error and the like can becorrected even more accurately than in the first embodiment in which thecorrection is performed by using a specific correction coefficient α.

[0151] Third Embodiment

[0152] The third embodiment is now explained. The external appearance ofthe electronic camera achieved in the third embodiment and its circuitblock diagram are identical to those of the electronic camera 1 in thefirst embodiment. Accordingly, FIGS. 1A, 1B and 2 should be referred tofor their details, and their explanation is omitted. The electroniccamera 1 in the third embodiment may be set in a specified sizephotographing mode in which the subject is photographed by fixing thesize of the photographic range at the subject position to a selectedprinting size or a standard photographing mode which is equivalent tothe recording mode in an electronic camera in the related art. Eithermode is selected through the mode selector button 12.

[0153] The operation executed in the electronic camera 1 in the thirdembodiment is explained. In the electronic camera 1, the recording modeor the reproduction mode can be selected through the command dial 6. Therecording mode includes the standard photographing mode equivalent tothe recording mode in an electronic camera in the related art and thespecified size photographing mode in which an automatic zoom adjustmentis executed to match the photographic range at the subject position withthe printing size that has been set.

[0154] (Standard Photographing Mode)

[0155] Since the operation performed in the standard photographing modeis similar to that executed in an electronic camera in the related artand is also similar to that executed in the first embodiment, itsexplanation is omitted.

[0156] It is to be noted that the electronic camera 1 in the embodimenthas an electronic zoom function whereby an image can be electronicallyenlarged through interpolation processing implemented on image data inconformance to a magnification factor setting Y. The DSP 433 sets theelectronic zoom magnification factor Y in response to a command issuedby the CPU 439 and the image data undergo interpolation processingexecuted in conformance to the magnification factor setting Y. A zoomsignal generated by operating the zoom switching button 9, and ahalfway-press operation signal or a full-press operation signalresulting from an operation of the shutter release button 5 are input tothe CPU 439.

[0157] If the zoom switching button 9 is operated toward the telephotoside (T), the CPU 439 drives the lens drive circuit 430 to opticallyraise the zoom magnification factor. In addition, if the zoom switchingbutton 9 is continuously operated toward the telephoto side (T) evenafter the optical magnification factor reaches a predetermined maximumvalue, the electronic zoom magnification factor Y is determined incorrespondence to the extent to which the zoom switching button 9 isoperated. When the electronic zoom magnification factor is Y, the imagedata in the area ranging over 1/Y both along the vertical direction andalong the horizontal direction around the center of the subject imageare extracted. The DSP 433 implements a specific type of imageprocessing on the extracted image data and also executes interpolationprocessing on the brightness signals and the color difference signalscalculated through the image processing to interpolate them by amagnification factor of Y along the vertical and horizontal directions.

[0158] (Reproduction Mode)

[0159] If the reproduction mode is selected through the command dial 6,image data recorded in the memory card 424 are read and stored into thebuffer memory 436. Under normal circumstances, the image data mostrecently recorded into the memory card 424 or the image data recordedinto the memory card 424 the earliest are read. The image data stored inthe buffer memory 436 are read out by the CPU 439, processed by the DSP433 so that they can be used as display image data and then theprocessed image data are displayed as a reproduced image at the displayLCD 3. It is to be noted that if no image data have been recorded in thememory card 424, a message indicating that there are no image data isdisplayed at the display LCD 3.

[0160] If the selector button 11 a or 11 c in FIG. 1 is operated while areproduced image is displayed at the display LCD 3, the image data inthe preceding frame are read out from the memory card 424 and thereproduced image of the image data is displayed at the display LCD 3.If, on the other hand, the selector button 11 b or 11 d is operated, theimage data in the succeeding frame are read and the reproduced image ofthe image data are brought up on the display LCD 3. Thus, in thereproduction mode, a reproduced image is displayed at the display LCD 3but the subject image captured by the CCD 214 cannot be displayed as inthe photographing mode. In addition, no focal adjustment operation orexposure detection for photographing purposes is executed in thereproduction mode.

[0161] (Specified Size Photographing Mode)

[0162] Next, the specified size photographing mode is explained. Asexplained above, a zoom adjustment is executed in the specified sizephotographing mode so as to match the photographic range with theprinting size which has been set. In the following explanation, S and Ware used to respectively refer to the printing size and the photographicrange. In the electronic camera 1 in the embodiment, the desirable sizecan be specified from a plurality of printing sizes S set in advance.The desirable size is selected by using the menu button 10 and theselector buttons 11 a˜11 d explained earlier. More specifically, aprinting size setting menu is brought up on display at the display LCD 3through the menu button 10. Symbols each representing one of the varioussizes are displayed in the printing size setting menu, and by selectingone of them with the selector buttons 11 a˜11 d, the photographic rangeW is set to the selected size S.

[0163] For instance, let us assume that the printing size S is set at A4size. If the shutter release button 5 is pressed half-way down in thissituation, the photographic optical system 2 is driven so as to projectan A4 size range in the subject over the entire image-capturing surfaceof the CCD 214. As a result, the image over the A4 size photographicrange is displayed over the entire display LCD 3.

[0164] Since the camera system used to execute operations forphotographing the subject through printing the image at themagnification factor 1 is identical to that shown in FIG. 3, inreference to which the first embodiment has been explained, itsexplanation is omitted.

[0165]FIG. 17 presents a schematic flowchart of the procedure of theoperations, from photographing through printing, executed in the camerasystem shown in FIG. 3. In FIG. 17, the photographing processing isexecuted in steps S1101 through S1103 at the camera 1, and the printingprocessing is executed in steps S1104 through S1107. The printing size Sis set in advance by operating the menu button 10 and the selectorbuttons 11 a˜11 d.

[0166] In step S1101, the photographing mode is switched from thestandard photographing mode to the specified size photographing modewith the mode selector button 12. It is to be noted that while theprinting size S is set in advance as described above, it may instead beset when switching the mode. In addition, a mark 33 indicating theprinting size S may be displayed at the display LCD 3 or the displaypanel 7 in the specified size photographing mode as detailed later (seeFIG. 21). In step S1102, a photographing operation is performed in thecamera in the specified size photographing mode. In step S1103, theheader information which includes the printing size setting S and theimage data are recorded into the memory card 424.

[0167] In step S1104, the header information and the image data are readinto the personal computer 20 from the camera 1 by, for instance,ejecting the memory card 424 from the camera 1 and loading it into thepersonal computer 20 shown in FIG. 3. In step S1105, image processing isexecuted in conformance to the printing size setting S or the printingresolution which is to be detailed later. It is to be noted that paperin the size matching the printing size S indicated at the display LCD 3or the display panel 7 of the electronic camera 1 has been loaded intothe printer 23. In step S1106, the size of the paper used in theprinting operation is displayed at the display monitor 22. In stepS1107, the printer 23 prints the image at the magnification factor of 1.

[0168] Next, the procedure executed on the camera side, corresponding tosteps S1101 to S1103 in FIG. 17, is explained in further detail inreference to the flowchart presented in FIGS. 18 and 19. FIGS. 18 and 19present a flowchart of the processing procedure of a program executed inthe CPU 439 at the camera 1. In step S1201, a decision is made as towhether or not the specified size photographing mode has been selectedthrough an operation of the mode selector button 12. If it is decided instep S1201 that the specified size photographing mode has been selected,the operation proceeds to step S1202. If, on the other hand, it isdecided in step S1201 that the specified size photographing mode has notbeen selected, i.e., the camera is currently set in the standardphotographing mode, the operation proceeds to step S1206 to execute asequence of processing in the standard photographing mode.

[0169] In step S1202, the position of the photographic optical system 2is adjusted to a predetermined macro position. Namely, the photographicoptical system 2 is automatically set to the macro position since thephotographic range W matching the printing size S (e.g., A4 or B5 size)is projected over the entire image-capturing surface of the CCD 214thereby setting the subject in an extremely close range in the specifiedsize photographing mode. In step S1203, an indicator of the printingsize S which has been set is brought up on the display LCD 3 or thedisplay panel 7.

[0170] In step S1204, a decision is made as to whether or not the macromode has been cleared through a user operation of an operating member(not shown). If it is decided in step S1204 that the macro mode has beencleared, the operation proceeds to step S1206, whereas if it is decidedthat the macro mode has not been cleared, the operation proceeds to stepS1205. In step S1205, a decision is made as to whether or not theshutter release button 5 has been pressed halfway down, and theoperation proceeds to step S1207 if it is decided that the shutterrelease button 5 has been pressed halfway down, whereas the operationreturns to step S1201 if it is decided the shutter release button 5 hasnot been pressed halfway down.

[0171] In step S1207, a focal adjustment operation for the photographicoptical system 2 is executed by the lens drive circuit 430 and thedistance L to the subject during the focal adjustment operation iscalculated. In step S1208, the focal length f0 at which the photographicrange W matching the printing size S is projected over the entireimage-capturing area and the printing resolution k which is to bedetailed later are calculated.

[0172] In FIG. 20, which shows the relationship between the subject andthe CCD 214, the photographic range W matching the printing size S isprojected over the entire image-capturing area at the CCD 214. It is tobe noted that the letter W indicating the photographic range in FIG. 20represents the longer side of the photographic range at the subjectposition, i.e., the lateral dimension of the photographic range when thecamera 1 shown in FIG. 1 is heldin a normal position, and corresponds tothe larger value of the dimensions of the printing size S (e.g., A4size). In addition, N indicates the number of pixels along the width ofthe image-capturing area at the CCD 214 and P indicates the pixel pitch.The relationship expressed in an expression (101) below is achieved bythe focal length f0, the distance f′ between the photographic opticalsystem 2 and the image-capturing surface and the subject distance L atall times.

1/L+1/f′=1/f0  (101)

[0173] When the photographic range W matching the printing size S isprojected over the entire image-capturing area at the CCD 214, thefollowing expression (102) is true for f′ in FIG. 20. In other words,the focal length f0 should be adjusted so as to satisfy both expressions(101) and (102).

f′/L=N·P/S

f′=(N·P·L)/S  (102)

[0174] In addition, since N pixels correspond to the dimension W (=S)(mm) as shown in FIG. 20, the printing resolution k should be set to avalue expressed in an expression (103) below to print the image capturedby the CCD 214 at the printing size S. In step S1208 described above,the focal length f0 is calculated by using expressions (101) and (102)and, in addition, the printing resolution k is calculated through anexpression (103) below.

k=N/S  (103)

[0175] In step S1209, a decision is made as to whether or not the focallength f0 calculated in step S1208 is larger than the maximum focallength fmax on the telephoto side of the photographic optical system 2.If it is decided that f0≦fmax in step S1209, the operation proceeds tostep S1216, whereas if it is decided that f0>fmax, the operationproceeds to step S1210. When f0>fmax, a range larger than thephotographic range 31 of the subject image 30 is displayed at thedisplay LCD 3 as shown in FIG. 21A even if the photographic opticalsystem 2 is zoomed up to fmax.

[0176] In step S 1210, a decision is made as to whether or not (f0/fmax)is larger than a predetermined electronic zoom magnification factorMmax. It is to be noted that the following explanation is given on theassumption that the term “magnification factor” indicates a degree ofmagnification in relation to the length instead of a magnificationfactor in relation to the area. If it is decided in step S1210 that(f0/fmax)>Mmax, the operation proceeds to step S1211 to set the focallength f of the photographic optical system 2 to fmax and also to setthe electronic zoom magnification factor to Mmax. In step S1212, animage obtained by enlarging the image in FIG. 21A by a factor of Mmax isdisplayed as shown in FIG. 21B and a frame 32 indicating the printingsize S is superimposed on the display of the image. It is to be notedthat the mark 33 indicating the printing size S is displayed at theupper left corner of the display LCD 3. In this example presented inFIGS. 21A˜21C, the printing size S is A4 and the mark 33 indicates “A4”accordingly.

[0177] In step S1213, a warning that an image cannot be photographedover the photographic range W matching the printing size S is issued.This warning may be issued by generating a warning sound through aspeaker (not shown) provided at the camera 1 or by displaying a warningmessage at the display LCD 3 of the display panel 7. In the followingstep S1214, a printing correction flag (to be detailed later) is set to1 and the operation proceeds to step S1218 in FIG. 19.

[0178] If, on the other hand, it is decided in step S1210 that(f0/fmax)≦Mmax, the operation proceeds to step S1215. In step S1215, theimage over the photographic range 31 around the center ◯ of the displayLCD 3 is enlarged by a factor of (f0/fmax) through the electronic zoomfunction. Since the interpolation processing and the like are executedfor the electronic zoom enlargement, the number of pixels in theenlarged image is equal to the number of pixels at the CCD 214, and thevalue calculated step S1208 for the printing resolution k can bedirectly used. In FIG. 21C, which shows the image obtained by enlargingthe image in the photographic range 31 by the factor of (f0/fmax), anenlargement of the image in the photographic range 31 in FIG. 21A isdisplayed over the entire LCD 3.

[0179] In step S1216, a decision is made as to whether or not the focallength f0 calculated in step S1208 is smaller than the minimum focallength fmin on the wide-angle side. The operation proceeds to step S1213if it is decided in step S1216 the f0<fmin, whereas the operationproceeds to step S1217 if it is decided that f0≧fmin. If the operationproceeds to step S1217 from step S1216, the printing correction flag isreset to 0 in step S1217 before the operation proceeds to step S1218 inFIG. 19.

[0180] When it is decided in step S1216 that f0<fmin, on the other hand,the photographic range 31 is larger than the display LCD 3 as shown inFIG. 22 even if the focal length f0 of the photographic optical system 2is set to the lower limit value fmin and, as a result, only a part ofthe subject in the range 31 is displayed. In other words, a rangesmaller than the photographic range 31 is projected onto theimage-capturing area of the CCD 214 at the subject distance L underthese circumstances.

[0181] In step S1218 in FIG. 19, a decision is made as to whether or notthe shutter release button 5 has been pressed all the way down, and theoperation proceeds to step S1219 if it is decided that the shutterrelease button 5 has been pressed all the way down, whereas theoperation returns to step S1205 in FIG. 18 if it is decided that theshutter release button 5 has not been pressed all the way down. Forinstance, if f0<fmin, resulting in a state such as that shown in FIG.22, the distance from the subject should be increased so as to ensurethat the focal length f0 calculated in step S1208 satisfies f0≧fmin,instead of pressing the shutter release button 5 all the way down instep S1218. If the shutter release button 5 is continuously heldhalf-way down in this situation, the operation proceeds from step S1205to step S1207, whereas if the half-way pressed state has been cleared,the operation returns from step S1205 to step S1201.

[0182] In step S1219, the image captured at the CCD 214 is taken in. Instep S1220, a decision is made as to whether or not the printingcorrection flag is set to 1. If it is decided in step S1220 the flag isset to 1, the photographic range W is not projected onto the entireimage-capturing surface of the CCD 214, and, accordingly, the operationproceeds to step S1221 to recalculate the printing resolution k. Inother words, if the operation proceeds to step S1211 from step S1210 orto step S1213 from step S1216, the printing resolution k is recalculatedso as to print the subject image at the magnification factor of 1.

[0183] If, on the other hand, it is decided in step S1220 that the flagis set to 0, the photographic range W is projected onto the entireimage-capturing area, and, accordingly, the operation proceeds to stepS1222 without recalculating the printing resolution k.

[0184] When the operation proceeds to step S1211 from step S1210 in FIG.18, i.e., when the focal length f is set to fmax and the electronic zoommagnification factor is set to Mmax, as shown in FIG. 21B, the imagedisplayed over the entire display LCD is not printed with themagnification factor of 1 and instead is printed at the printing size S,if it is printed at the printing resolution k calculated by using theexpression (103). The subject image shown in FIG. 21C is an enlargementachieved by magnifying the subject image in FIG. 21A by a factor of(f0/fmax) and the subject image shown in FIG. 21B is obtained byenlarging the subject image in FIG. 21A by a factor of Mmax. Thus, byenlarging the image shown in FIG. 21B by a factor of (f0/fmax)/Mmax, thesubject image in the frame 32 can be displayed over the entire displayLCD 3. Accordingly, if the printing resolution k calculated through theexpression (103) is lowered by dividing it with (f0/fmax)/Mmax as shownin an expression (104) below, the subject image in the frame 32 can beprinted at the printing size S.

k=(N/S)/{(f0/fmax)/Mmax}=(N/S)·(Mmax·fmax/f0)  (104)

[0185] If, on the other hand, the operation proceeds from step S1216 tostep S1213, i.e., if the photographic range 31 is larger than thedisplay LCD 3 as shown in FIG. 22, it is necessary to raise the printingresolution k. If the size of the image in the range 31 in the FIG. 22 isaltered by a magnification factor of (f0/fmin), the size of the imagebecomes equal to the size of the display LCD 3. Namely, by multiplyingthe printing resolution k calculated by using expression (103) by afactor of (fmin/f0) as shown in an expression (105) below, the imageover the range 31 can be printed at the printing size S.

k=(N/S)·(fmin/f0)  (105)

[0186] Then, the image data are compressed in a predetermined format instep S1222. In step S1223, tag information indicating the printing sizeS, the printing resolution k, the focal length f, the subject distanceL, the number of pixels N and the like is recorded into the memory card424 together with the compressed image data. Thus, the sequence ofprocessing from photographing through recording, executed at theelectronic camera 1, is completed.

[0187] It is to be noted that if the printing resolution k is to berecorded in the TIFF format, the printing resolution k is recorded inunits corresponding to the resolution along the width of the image, theresolution along the height of the image and the resolution along thewidth and the height of the image respectively defined by tag numbers282˜284. If, on the other hand, the printing resolution k is recorded inthe Exif format, individual pieces of information indicating the subjectdistance, the lens focal length, the resolution along the height of thefocal plane, the resolution along the width of the focal plane and theresolution over the focal plane as defined by tag numbers 37386, 37382,41486˜41488 are recorded and, in this case, the printing resolution kmay be calculated by the printing application software program. Thefocal plane resolution mentioned above is the reciprocal of the pitch Pof the pixels at the CCD 214.

[0188] This subject image is printed on the printer 23 connected to thepersonal computer 20 by taking the image data into the personal computer20 shown in FIG. 3 as described earlier. If the printer 23 is loadedwith printing paper in the printing size S, the subject image is printedat a magnification factor substantially set to 1. It is to be noted thatif the peripheral area of the printing paper is to be left unprinted asa margin, the subject image is printed at a size S slightly smaller thanthe size corresponding to the magnification factor 1. In addition, ifthe printer 23 is loaded with paper that is larger than the printingsize S, too, the image can be printed at the magnification factor of 1by setting the resolution of the printing operation equal to theprinting resolution k stored in memory as tag information.

[0189] The third embodiment explained above achieves the followingfeatures.

[0190] (a) When the electronic camera 1 is set in the specified sizephotographing mode, the photographic optical system 2 is automaticallyadjusted to set the photographic range to the specified size. As aresult, the subject image is displayed at the display LCD 3 over a rangematching the range of the image to be printed on paper in the specifiedsize. Thus, a photographing operation can be performed while checkingthe state of the image as it will be printed and, as a result, adesirable subject image can be obtained through the photographingoperation.

[0191] (b) If the subject distance is too large or too small, the frame32 is brought up on display at the display LCD 3, as shown in FIG. 21Bor a warning is issued to alert the user that the subject distance isnot correct.

[0192] (c) By loading printing paper in a size of matching it theprinting size indicated at the display LCD 3 or the display panel 7, thesubject image can be printed in a size matching to the actual subject.

[0193] (d) Even if the size of the printing paper in the printer doesnot match the printing size indicated at the display LCD 3 or thedisplay panel 7, the subject image can be printed at the magnificationfactor of 1 with ease by printing it at the printing resolution k storedin memory as tag information.

[0194] While a specific photographic range can be selected from aplurality of sizes in the third embodiment explained above, thephotographic range may be set at a predetermined uniform size in theelectronic camera. In such a case, the printing size may be indicated atthe position of the mode selector button 12 instead of indicating theprinting size at the display LCD 3 or the display panel 7. By loadingthe printer 23 with printing paper in the size matching the printingsize indicated at the mode selector button 12, the image can beautomatically printed at the magnification factor of 1.

VARIATION EXAMPLE 1

[0195] In Variation Example 1, the control is implemented as shown inthe flowchart presented in FIG. 23 instead of the flowchart presented inFIG. 18. The same step numbers are assigned to steps in the flowchart inFIG. 23 in which processing identical to that in FIG. 18 is executed,and steps S1301 and S1302 differentiate the flowchart in FIG. 23 fromthe flowchart in FIG. 18. In addition, since the procedure continuingfrom FIG. 23 is identical to that shown in FIG. 19, its illustration andexplanation are omitted.

[0196] In Variation Example 1, once it is decided in step S1201 that thespecified size photographing mode has been selected, the operationproceeds to step S1301 to move the photographic optical system 2 to thetelephoto end in the macro range. This reduces the field depth of thelens and raises the accuracy with which the distance L is measured. As aresult, the zoom magnification factor can be set with an even higherdegree of accuracy.

[0197] In addition, if it is decided in step S1216 that f0<fmin, i.e.,if the subject distance L is too small and thus, the photographic range31 is still larger than the display LCD 3 as shown in FIG. 22 even withthe photographic optical system 2 set at the wide-angle end (f fmin),the operation proceeds to step S1302 to sub-sample the pixels so as toreduce the size of the photographic image by a factor of (f0/fmin). Oncethe sub-sampling processing in step S1302 is completed, the operationproceeds to step S1217 to reset the printing correction flag to 0.Namely, if the sub-sampling processing is executed in step S1302, it isnot necessary to recalculate the printing resolution k.

VARIATION EXAMPLE 2

[0198]FIG. 24 presents a flowchart similar to that in FIG. 23 asVariation Example 2. In the flowchart presented in FIG. 24, differentprocessing is executed after it is decided in step S1216 that f0<fmin.Namely, if it is decided in step S1216 that f0<fmin, the operationproceeds to step S1401 to sub-sample pixels from the photographic imageto ¼ of the original volume and also to substitute the distance Lcalculated and stored in memory in step S1207 with 2·L.

[0199] When the pixels are sub-sampled to ¼ of the original volume, thepixel data of the image along the horizontal direction are sub-sampledto ½ and the pixel data along the vertical direction, too, aresub-sampled to ½. As a result, the length of the sides of the printedimage are halved, which is equivalent to doubling the subject distanceL. Once the processing in step S1401 is completed, the operationproceeded to step S1208 to calculate the focal length f0 by using thenew L that has replaced the original distance. In Variation Example 2,in which the pixels are sub-sampled to ¼ regardless of the size of thephotographic image, the sub-sampling processing is simplified comparedto that executed in Variation Example 1.

[0200] Fourth Embodiment

[0201] While the photographic range W matching the printing size S isspecified and the subject image over the range W is printed at themagnification factor 1 in the third embodiment, the subject image isprinted at a magnification factor of Z onto a printing paper matching aspecified printing size Sin the fourth embodiment. A desired printingmagnification factor Z is selected by operating the buttons 11 a˜11 d,from a plurality of printing magnification factors listed in a printingmagnification factor setting menu brought up on display at the displayLCD 3 through an operation of the menu button 10. When the specifiedsize photographing mode is selected through the mode selector button 12,the photographic range W is set to a value obtained by dividing thespecified printing size S by the printing magnification factor Z. It isto be noted that details of the method of photographic range setting areto be provided later. It is also to be noted that the structures of theelectronic camera 1, the camera system and the like are identical tothose in the first embodiment, and the following explanation focuses onthe method of control implemented when printing the subject image at themagnification factor Z.

[0202]FIG. 25 shows the relationship between the photographic range Wand the CCD 214. As in the third embodiment, the relationship expressedas an expression (101) below is achieved among the focal length f0, thedistance f′ between the photographic optical system 2 and theimage-capturing surface and the subject distance L.

1/L+1/f′1/f0  (101)

[0203] In order to print the subject image projected over the entireimage-capturing area of the CCD 214 onto printing paper matching theprinting size S at the magnification factor Z, the photographic rangeW=S/Z, calculated by multiplying the printing size S by a factor of(1/Z) needs to be projected onto the CCD 214 as shown in FIG. 25.Accordingly, the focal length f of the electronic camera 1 should beadjusted to a focal length f0 which satisfies both expression (101) andthe expression (106) below. As in the third embodiment, the printingresolution k is set as expressed in the expression (103).

f′/L=N·P/(S/Z) f′=(N·P·L·Z)/S  (106)

k=N/S  (103)

[0204] Since the overall procedure from the photographing operationthrough the printing operation executed in the camera system and theprocedure executed in the camera are identical to those in the thirdembodiment, their explanation is omitted. However, the printingmagnification factor Z, too, is stored in memory as tag information instep S1223 in FIG. 19 in the fourth embodiment. In the fourthembodiment, by loading the printer 23 with printing paper in a sizematching the printing size S set for the photographing operation, thesubject image is automatically printed at the magnification factor Z. Asa result, the subject image can be printed at the magnification factor Zwith great ease.

[0205] Fifth Embodiment

[0206] In the third and fourth embodiments, the printing size S is inputto the electronic camera 1 and the photographic optical system 2 iscontrolled based upon the printing size S. In the fifth embodiment, acalibration is performed so as to project the photographic range Wmatching the printing-enabled range onto the CCD 214 by using a chart onwhich the printing-enabled range for the printer 23 is printed. It is tobe noted that the calibration is executed after setting the electroniccamera 1 in a calibration mode by, for instance, operating the commanddial 6 shown in FIG. 1.

[0207] Before the calibration, the chart of the printing-enabled rangeshould be printed in advance with the printer 23. Under normalcircumstances, the peripheral area of the printing paper is an area overwhich printing is disabled and is, therefore, left blank, and therectangular area further inward relative to the peripheral area of theprinting paper is the printing-enabled range. For instance, when A4 sizepaper is used, an image is printed in a rectangular frame which isslightly smaller than A4 size.

[0208]FIG. 26 presents a flowchart of the calibration procedure, whichstarts as the calibration mode is set with the command dial 6. In stepS1501, the photographic optical system 2 of the electronic camera 1 isfirst set in the micro range and then the focal length is set to themaximum telephoto end (fmax). In this state, with the photographicoptical system 2 and the focal length sustaining the setting statusesselected in step S1501, the user holds the electronic camera 1 towardthe chart.

[0209] In step S1502, the distance Lmax to the chart is measured. InstepS1503, an image of the chart captured by the electronic camera 1 isbrought up on display at the display LCD 3. The user moves closer to, orfurther away from the chart until the rectangular frame of the chart ondisplay becomes completely aligned with the display frame at the displayLCD 3. Then, once the rectangular frame of the chart and the displayframe of the display LCD 3 are completely aligned with each other, theuser presses the shutter release button 5 all the way down.

[0210] In step S1504, a decision is made as to whether or not theshutter release button 5 of the electronic camera 1 has been pressed allthe way down, and the operation proceeds to step S1505 if an affirmativedecision (YES) is made, whereas the operation returns to step 1502 if anegative decision (NO) is made. In the calibration mode, the operationproceeds to step S1505 after the shutter release button 5 is pressed allthe way down to execute a focussing operation alone.

[0211] In step S1506, the photographic optical system 2 is set in themacro range and then the focal length is set to the minimum wide-angleend (fmin). Next, the user holds the electronic camera 1 toward thechart again. In step S1507, the distance Lmin to the chart is measured,and in the following step S1508, an image of the chart is displayed atthe display LCD 3. In this case, too, the user moves closer to orfurther away from the chart until the rectangular frame of the chartmatches the display frame of the display LCD 3, and the user thenpresses the shutter release button 5 all the way down when therectangular frame and the display frame are completely aligned with eachother.

[0212] In step S1509, a decision is made as to whether or not theshutter release button 5 has been pressed all the way down and theoperation proceeded to step S1510 if an affirmative decision (YES) ismade, whereas the operation returns to step S1507 if a negative decision(NO) is made. Subsequently, after a focussing operation is executed instep S1510, the distances Lmin and Lmin are stored in memory in stepS1511 before the sequence of the calibration processing ends.

[0213] After the calibration processing, the electronic camera 1 iscontrolled so as to set the focal length to f0 calculated through anexpression (107) based upon the distances Lmin and Lmin stored in memoryin the specified size photographing mode. As a result, the photographicrange W matching the size of the rectangular frame of the chart isprojected onto the entire image-capturing area of the CCD 214, and thephotographed subject image can be printed onto printing paper in size Sat the magnification factor of 1.

f0=fmin+{(fmax−fmin)/(Lmax−Lmin)}·(L−Lmin)  (107)

[0214] In the third and fourth embodiments explained earlier, thephotographic range W matching the printing size S is projected over theentire image-capturing area of the CCD 214 by adjusting the focal lengthf0 so that f′ in FIG. 20 satisfies the following expressions (101) and(102). However, factors such as an error attributable to inconsistencyamong individual lenses are not taken into consideration in expression(102) and, for this reason, expression (102) may be modified toexpression (108) for higher accuracy by using an error correctioncoefficient α. In other words, in the third and fourth embodiments, inwhich the correction coefficient α is not used, the accuracy of thefocal adjustment is poorer.

1/L+1/f′1/f0  (101)

f′=(N·P·L)/W  (102)

f′=(N·P·L)/(W·α)  (108)

[0215] However, since the focal length f0 is calculated based on thedata Lmin and Lmin obtained by actually projecting the rectangular frameof the chart over the entire image-capturing area of the CCD 214 in thefifth embodiment, the focal length f0 is calculated by taking intoconsideration the effect of any lens error. For this reason, a higherdegree of accuracy is achieved in the control compared to the third andfourth embodiments.

[0216] While an explanation is given above in reference to the third andfourth embodiments on an example in which the electronic camera and thecamera system achieve both the optical zoom function and the electroniczoom function, the present invention may also be adopted in anelectronic camera and a camera system achieving only either of thesefunctions. In addition, while the printing resolution k is calculated atthe camera, it may instead be calculated at the means for printing basedupon the number of pixels N and the printing size S taken from thecamera into the means for printing (the PC 20 and the printer 23).

[0217] It is to be noted that while the printing resolution k iscalculated in the electronic camera 1 in the embodiments describedabove, the printing resolution k may instead be calculated in thepersonal computer or the printer 23 on the printing side based upon thesubject distance L, the focal length f, the number of pixels N, thepixel pitch P and the printing magnification factor M recorded as thetag information, as explained earlier. In the latter case, the controlprogram executed at the personal computer 20 may be provided in arecording medium such as a CD-ROM or through a data signal on theInternet or the like.

[0218]FIG. 27 shows how this may be achieved. A personal computer 100corresponds to the personal computer 20. The personal computer 100receives the program via a CD-ROM 104. In addition, the personalcomputer 100 can be connected to a communication line 101. In a computer102, i.e., the server computer that provides the program, the program isstored in a recording medium such as a hard disk 103. The communicationline 101 may be a communication line for Internet communication,personal computer communication or the like or it may be a dedicatedcommunication line. The computer 102 reads out the program from the harddisk 103 and transmits the program to the personal computer 100 via thecommunication line 101. In other words, the program is embodied as adata signal on a carrier wave which is transmitted via the communicationline 101. Thus, the program can be distributed as a computer-readablecomputer program product assuming any of various forms such as arecording medium and a carrier wave.

[0219] In addition, the control program according to the presentinvention, which is executed within the electronic camera in theembodiments is normally installed in a ROM or the like during themanufacturing process. However, by installing the control program in aROM which allows an overwrite and connecting the ROM to a computerassuming a structure achieved by combining the structures shown in FIGS.3 and 17, a program upgrade can be received from a recording medium suchas a CD-ROM via the computer. Furthermore, the program upgrade can beprovided via the Internet or the like in a manner similar to thatexplained earlier.

[0220] The above described embodiments are examples, and variousmodifications can be made without departing from the spirit and scope ofthe invention.

What is claimed is:
 1. A method for image data print control,comprising: obtaining subject image data which is obtained by capturingan image of a subject formed through a photographic optical system andoutput by an image-capturing element having a plurality of pixels;obtaining a distance to the subject; obtaining a number of pixelsprovided at the image-capturing element; obtaining a pixel pitch at theimage-capturing element; obtaining a focal length of the photographicoptical system; and calculating a printing resolution so as to print theimage of the subject in a size equal to a size of the subject by usingthe subject image data, based upon the distance to the subject, thenumber of pixels at the image-capturing element, the pixel pitch at theimage-capturing element and the focal length of the photographic opticalsystem.
 2. A method for image data print control according to claim 1,further comprising: obtaining a printing magnification factor, wherein:after the printing magnification factor is obtained, a printingresolution is calculated so as to print the image of the subject in asize achieved by enlarging the size of the subject by the printingmagnification factor that has been obtained by using the subject imagedata, based upon the distance to the subject, the number of pixels atthe image-capturing element, the pixel pitch at the image-capturingelement and the focal length of the photographic optical system.
 3. Anelectronic camera, comprising: a photographic optical system; animage-capturing element having a plurality of pixels that captures animage of a subject formed through the photographic optical system andoutputs image data constituting the image thus obtained; a range findingdevice that detects a distance to the subject; a calculating device thatobtains a number of pixels at the image-capturing element, a pixel pitchat the image-capturing element and a focal length of the photographicoptical system, and calculates a printing resolution so as to print theimage of the subject in a size equal to a size of the subject by usingthe subject image data, based upon the distance to the subject that hasbeen detected, the number of pixels at the image-capturing element, thepixel pitch at the image-capturing element and the focal length of thephotographic optical system; and a recording control device that recordsthe printing resolution that has been calculated into a recording mediumtogether with the image data.
 4. An electronic camera, comprising: animage-capturing unit that implements photoelectric conversion on asubject image projected onto an image-capturing area by a photographicoptical system; a range finding unit that detects a subject distance; aphotographic range calculating unit that calculates a photograph rangeover which the image-capturing area at the image-capturing unit isprojected at a position corresponding to the subject distance by thephotographic optical system; a printing resolution calculating unit thatcalculates a printing resolution so as to print the subject image basedupon image information output by the image-capturing unit in a sizesubstantially equal to the photographic range, based upon thephotographic range and the number of pixels provided at theimage-capturing unit; and a storage control unit that stores theprinting resolution into a storage area together with the imageinformation.
 5. An electronic camera, comprising: an image-capturingunit that implements photoelectric conversion on a subject imageprojected onto an image-capturing area by a photographic optical system;a range finding unit that detects a subject distance; a photographicrange calculating unit that calculates a photograph range over which theimage-capturing area at the image-capturing unit is projected at aposition corresponding to the subject distance by the photographicoptical system; a magnification factor setting unit that sets a printingmagnification factor; a printing resolution calculating unit thatcalculates a printing resolution so as to print the subject image basedupon image information output by the image-capturing unit in a sizesubstantially equal to a size achieved by multiplying a size of thephotographic range by the printing magnification factor, based upon thephotographic range, a number of pixels provided at the image-capturingunit and the printing magnification factor; and a storage control unitthat stores the printing resolution into a storage area together withthe image information.
 6. An electronic camera according to claim 4,further comprising: a display monitor that selectively displays asubject image captured by the image-capturing unit and a subject imagebased upon the image information stored in the storage area, wherein: adisplay magnification factor representing a ratio of a size of a displayrange of the display monitor and a value obtained by dividing the numberof pixels by the printing resolution is displayed at the display monitortogether with the subject image.
 7. An electronic camera according toclaim 4, wherein: the photographic optical system is constituted of azoom optical system; and an execution mode in which the printingresolution is calculated and the printing resolution is stored into thestorage area and a non-execution mode in which no printing resolution iscalculated and stored are provided, the electronic camera furthercomprising: a mode setting unit that selectively sets either theexecution mode or the non-execution mode; a zoom changing unit thatchanges a focal length of the zoom optical system; and a zoom controlunit that controls the zoom changing unit so that a zoom position of thezoom optical system achieves a predetermined focal length when the modesetting unit sets the execution mode.
 8. An electronic camera accordingto claim 7, wherein: the zoom control unit controls the zoom changingunit so that the zoom optical system enters a macro photographing statewhen the mode setting unit sets the execution mode.
 9. An electroniccamera according to claim 8, further comprising: a clearing unit thatclears the macro photographing state; and a mode control unit thatswitches from the execution mode to the non-execution mode when theclearing unit clears the macro photographing state in the executionmode.
 10. An electronic camera according to claim 4, further comprising:a warning unit that engages in a warning operation when the subjectdistance is not within a predetermined range.
 11. A camera system,comprising: an electronic camera; and a printing device, wherein theelectronic camera comprises: an image-capturing unit that implementsphotoelectric conversion on a subject image projected onto animage-capturing area by a photographic optical system; a range findingunit that detects a subject distance; a photographic range calculatingunit that calculates a photograph range over which the image-capturingarea at the image-capturing unit is projected at a positioncorresponding to the subject distance by the photographic opticalsystem; a printing resolution calculating unit that calculates aprinting resolution so as to print the subject image based upon imageinformation output by the image-capturing unit in a size substantiallyequal to the photographic range, based upon the photographic range and anumber of pixels provided at the image-capturing unit; and a storagecontrol unit that stores the printing resolution into a storage areatogether with the image information, and the printing device prints thesubject image based upon the printing resolution and the imageinformation stored in the storage area.
 12. A camera system, comprising:an image-capturing unit that implements photoelectric conversion on asubject image projected onto an image-capturing area by a photographicoptical system; a range finding unit that detects a subject distance; aphotographic range calculating unit that calculates a photograph rangeover which the image-capturing area at the image-capturing unit isprojected at a position corresponding to the subject distance by thephotographic optical system; a printing resolution calculating unit thatcalculates a printing resolution so as to print the subject image basedupon image information output by the image-capturing unit in a sizesubstantially equal to the photographic range, based upon thephotographic range and a number of pixels provided at theimage-capturing unit; and a printing device that prints the subjectimage based upon the printing resolution and the image information. 13.A camera system according to claim 11, further comprising: an imageprocessing unit that processes the image information if the printingresolution is not within a printing resolution range set in advance, soas to achieve a predetermined printing resolution within the printingresolution range, wherein: the printing device prints the subject imagebased upon the image information having been processed at the imageprocessing unit and the predetermined printing resolution.
 14. A camerasystem according to claim 12, further comprising: an image processingunit that processes the image information if the printing resolution isnot within a printing resolution range set in advance, so as to achievea predetermined printing resolution within the printing resolutionrange, wherein: the printing device prints the subject image based uponthe image information having been processed at the image processing unitand the predetermined printing resolution.
 15. An electronic camera,comprising: an image-capturing unit that implements photoelectricconversion on a subject image projected onto an image-capturing area bya photographic optical system; a range finding unit that detects asubject distance; a photographic range calculating unit that calculatesa photograph range over which the image-capturing area at theimage-capturing unit is projected at a position corresponding to thesubject distance by the photographic optical system; a printingresolution calculating unit that calculates a printing resolution so asto print the subject image based upon image information output by theimage-capturing unit in a size substantially equal to the photographicrange, based upon the photographic range and a number of pixels providedat the image-capturing unit; a storage control unit that stores theprinting resolution into the storage area together with the imageinformation; a display monitor that displays the subject image capturedby the image-capturing unit; a printing size storage unit having storedtherein at least one of various printing sizes; and a monitor controlunit that controls the display monitor so as to display at least one ofmarks indicating the printing sizes together with the subject image. 16.An electronic camera according to claim 15, wherein: a reproduction modein which the subject image based upon the image information stored inthe storage area is displayed at the display monitor, is provided; andwhen the reproduction mode is selected, the monitor control unitcontrols the display monitor so as to display the mark together with thesubject image.
 17. An electronic camera according to claim 15, furthercomprising: an input unit that inputs the printing sizes to the printingsize storage unit.
 18. An electronic camera according to claim 15,wherein: the mark displayed at the display monitor is a rectangularframe indicating the printing size.
 19. An electronic camera accordingto claim 18, further comprising: a correction unit that captures animage of a reference rectangular frame having a size equal to theprinting size and corrects the printing resolution based upon a printingresolution at which the rectangular frame corresponding to the printingsize matches the image of the reference rectangular frame on the displaymonitor and a value obtained by dividing the number of pixels by thesize of the reference rectangular frame, wherein: the storage controlunit stores the printing resolution having been corrected by thecorrection unit into the storage area together with the imageinformation.
 20. An electronic camera according to claim 15, wherein:the monitor control unit controls the display monitor so as to display acenter mark indicating a central position of the display monitor.
 21. Anelectronic camera according to claim 15, further comprising: a selectionunit that selects one of the printing sizes stored in the printing sizestorage unit; and a decision-making unit that makes a decision as towhether or not the photographic range calculated by the photographicrange calculating unit is equal to or smaller than the printing sizeselected by the selection unit, wherein: the monitor control unitcontrols the display monitor so as to display a decision making markindicating decision results obtained at the decision-making unit.
 22. Anelectronic camera comprising: a zoom changing unit that changes a focallength of a zoom lens; an image-capturing unit that executesphotoelectric conversion for a subject image projected by the zoom lensonto an image-capturing area; a range finding unit that detects adistance to a subject; a photographic range setting unit that sets asize of a photographic range at a subject position; and a zoom controlunit that controls the zoom changing unit based upon the photographicrange that has been set and the subject distance so that the subjectwithin the photographic range is projected almost over the entirety ofthe image-capturing area.
 23. An electronic camera comprising: a zoomchanging unit that changes a focal length of a zoom lens; animage-capturing unit that executes photoelectric conversion for an imageof a subject projected by the zoom lens onto an image-capturing area; arange finding unit that detects a distance to a subject; a mode settingunit operated to set a specified range photographing mode in which asize of the photographic range at a subject position is fixed at apredetermined size; and a zoom control unit that controls the zoomchanging unit based upon the photographic range and the subject distancewhen the specified range photographing mode is set so that the subjectwithin the photographic range is projected almost over the entirety ofthe image-capturing area.
 24. An electronic camera according to claim23, further comprising: a magnification factor setting unit that sets aprinting magnification factor, wherein: the mode setting unit fixes thesize of the photographic range at the subject position to a sizecalculated by dividing the predetermined size by the printingmagnification factor.
 25. An electronic camera according to claim 23,further comprising: a size setting unit operated to set thepredetermined size.
 26. An electronic camera comprising: a zoom changingunit that changes a focal length of a zoom lens; an image-capturing unitthat executes photoelectric conversion for an image of a subjectprojected by the zoom lens onto an image-capturing area; a range findingunit that detects a distance to a subject; a mode setting unit operatedto set a specified range photographing mode in which a size of thephotographic range at a subject position is fixed at a predeterminedsize; a focal length calculating unit that calculates a focal length atwhich the subject within the photographic range is projected almost overthe entirety of the image-capturing area when the specified rangephotographing mode is set, based upon (a) a plurality of focal lengthsassumed by the zoom lens, (b) subject distances detected incorrespondence to the plurality of focal lengths when a reference imageat the predetermined size is projected almost over the entirety of theimage-capturing area and (c) the distance to the subject detected whenan image of the subject is captured; and a zoom control unit thatcontrols the zoom changing unit so as to match the focal length of thezoom lens with the focal length calculated at the focal lengthcalculating unit.
 27. An electronic camera according to claim 23,further comprising: a display monitor at which a subject image basedupon image information provided by the image-capturing unit and a rangeindicator mark indicating a range substantially corresponding to thephotographic range superimposed on the subject image are brought up ondisplay when the focal length of the zoom lens is at a maximum and asize of a range of the subject projected almost over the entirety of theimage-capturing area is larger than the size of the photographic range.28. An electronic camera according to claim 27, further comprising: astorage control unit that stores image information over the rangeindicated by the range indicator mark into a storage area.
 29. Anelectronic camera according to claim 28, wherein: the storage controlunit stores the predetermined size into the storage area incorrespondence to the image information.
 30. An electronic cameraaccording to claim 23, further comprising: an electronic zoom unit thatelectronically enlarges a part of a subject image achieved based uponimage information provided by the image-capturing unit; and anelectronic zoom control unit that controls the electronic zoom unit whenthe focal length of the zoom lens is at a maximum and a size of a rangeof the subject projected almost over the entirety of the image-capturingarea is larger than the size of the photographic range, so as to enlargean image corresponding to the subject within the photographic range inthe subject image achieved based upon the image information from theimage-capturing unit to a size matching a size of the subject image. 31.An electronic camera according to claim 23, further comprising: awarning unit that issues a warning if the focal length of the zoom lensis at a minimum and a size of a range of the subject projected almostover the entirety of the image-capturing area is smaller than the sizeof the photographic range.
 32. An electronic camera according to claim23, further comprising: a sub-sampling unit that electronicallysub-samples the subject image when the focal length of the zoom lens isat a minimum and a size of a range of the subject projected almost overthe entirety of the image-capturing area is smaller than the size of thephotographic range.
 33. An electronic camera, comprising: a mode settingunit operated to set a specified range photographic mode in which a sizeof a photographic range at the subject position is fixed to apredetermined size; an image-capturing unit that executes photoelectricconversion for a subject projected onto an image-capturing area by aphotographic optical system; an electronic zoom unit that electronicallyenlarges a part of a subject image achieved based upon image informationprovided by the image-capturing unit; and an electronic zoom controlunit that controls the electronic zoom unit so as to enlarge an imagecorresponding to the photographic range in the subject image to a sizematching a size of the subject image.
 34. An electronic camera accordingto claim 23, further comprising: a display unit at which a markindicating the predetermined size is displayed.
 35. A camera systemcomprising: a zoom changing unit that changes a focal length of a zoomlens; an image-capturing unit that executes photoelectric conversion foran image of a subject projected by the zoom lens onto an image-capturingarea; a range finding unit that detects a distance to a subject; a modesetting unit operated to set a specified range photographing mode inwhich a size of the photographic range at a subject position is fixed ata predetermined size; and a zoom control unit that controls the zoomchanging unit based upon the photographic range and the subject distancewhen the specified range photographing mode is set so that the subjectwithin the photographic range is projected almost over the entirety ofthe image-capturing area; and a printing device that prints an imagephotographed in the specified range photographing mode in a sizesubstantially matching the predetermined size.
 36. A computer-readablecomputer program product containing a control program for image dataprint control, the control program for image data print controlcomprising: an instruction for obtaining subject image data which isobtained by capturing an image of the subject formed through aphotographic optical system output by an image-capturing element havinga plurality of pixels; an instruction for obtaining a distance to thesubject; an instruction for obtaining a number of pixels provided at theimage-capturing element; an instruction for obtaining a pixel pitch atthe image-capturing element; an instruction for obtaining a focal lengthof the photographic optical system; and an instruction for calculating aprinting resolution so as to print the subject image in a size equal toa size of the subject by using the subject image data, based upon thedistance to the subject, the number of pixels at the image-capturingelement, the pixel pitch at the image-capturing element and the focallength of the photographic optical system.
 37. A computer-readablecomputer program product according to claim 22, wherein: thecomputer-readable computer program product is a recording medium inwhich the control program for image data print control is recorded. 38.A computer-readable computer program product according to claim 22,wherein: the computer-readable computer program product is a carrierwave in which the control program for image data print control isembodied as a data signal.